Initial commit

application/Espo/ORM/Query/BaseBuilderTrait.php

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+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use RuntimeException;
+
+trait BaseBuilderTrait
+{
+    /**
+     * Must be protected for compatibility reasons.
+     *
+     * @var array<string, mixed>
+     */
+    protected $params = [];
+
+    public function __construct()
+    {
+    }
+
+    private function isEmpty(): bool
+    {
+        return empty($this->params);
+    }
+
+    private function cloneInternal(Query $query): void
+    {
+        if (!$this->isEmpty()) {
+            throw new RuntimeException("Clone can be called only on a new empty builder instance.");
+        }
+
+        $this->params = $query->getRaw();
+    }
+}

application/Espo/ORM/Query/BaseTrait.php

@@ -0,0 +1,70 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+trait BaseTrait
+{
+    /**
+     * @var array<string, mixed>
+     */
+    private $params = [];
+
+    /**
+     * Get parameters in RAW format.
+     *
+     * @return array<string, mixed>
+     */
+    public function getRaw(): array
+    {
+        return $this->params;
+    }
+
+    /**
+     * Create from RAW params.
+     *
+     * @param array<string, mixed> $params
+     */
+    public static function fromRaw(array $params): self
+    {
+        $obj = new self();
+
+        $obj->validateRawParams($params);
+
+        $obj->params = $params;
+
+        return $obj;
+    }
+
+    /**
+     * @param array<string, mixed> $params
+     */
+    private function validateRawParams(array $params): void
+    {}
+}

application/Espo/ORM/Query/Builder.php

@@ -0,0 +1,42 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+/**
+ * Builds query parameters.
+ * Builder instances are one-off, meaning that you need to instantiate it for every new building process.
+ */
+interface Builder
+{
+    /**
+     * Build a query instance.
+     */
+    public function build(): Query;
+}

application/Espo/ORM/Query/Delete.php

@@ -0,0 +1,81 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use RuntimeException;
+
+/**
+ * Delete parameters.
+ *
+ * Immutable.
+ */
+class Delete implements Query
+{
+    use SelectingTrait;
+    use BaseTrait;
+
+    /**
+     * Get an entity type.
+     */
+    public function getFrom(): string
+    {
+        return $this->params['from'];
+    }
+
+    /**
+     * Get a from-alias
+     */
+    public function getFromAlias(): ?string
+    {
+        return $this->params['fromAlias'] ?? null;
+    }
+
+    /**
+     * Get a LIMIT.
+     */
+    public function getLimit(): ?int
+    {
+        return $this->params['limit'] ?? null;
+    }
+
+    /**
+     * @param array<string, mixed> $params
+     */
+    private function validateRawParams(array $params): void
+    {
+        $this->validateRawParamsSelecting($params);
+
+        $from = $params['from'] ?? null;
+
+        if (!$from || !is_string($from)) {
+            throw new RuntimeException("Select params: Missing 'from'.");
+        }
+    }
+}

application/Espo/ORM/Query/DeleteBuilder.php

@@ -0,0 +1,88 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use RuntimeException;
+
+class DeleteBuilder implements Builder
+{
+    use SelectingBuilderTrait;
+
+    /**
+     * Create an instance.
+     */
+    public static function create(): self
+    {
+        return new self();
+    }
+
+    /**
+     * Build a DELETE query.
+     */
+    public function build(): Delete
+    {
+        return Delete::fromRaw($this->params);
+    }
+
+    /**
+     * Clone an existing query for a subsequent modifying and building.
+     */
+    public function clone(Delete $query): self
+    {
+        $this->cloneInternal($query);
+
+        return $this;
+    }
+
+    /**
+     * Set FROM parameter. For what entity type to build a query.
+     */
+    public function from(string $entityType, ?string $alias = null): self
+    {
+        if (isset($this->params['from'])) {
+            throw new RuntimeException("Method 'from' can be called only once.");
+        }
+
+        $this->params['from'] = $entityType;
+        $this->params['fromAlias'] = $alias;
+
+        return $this;
+    }
+
+    /**
+     * Apply LIMIT.
+     */
+    public function limit(?int $limit = null): self
+    {
+        $this->params['limit'] = $limit;
+
+        return $this;
+    }
+}

application/Espo/ORM/Query/Insert.php

@@ -0,0 +1,72 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use RuntimeException;
+
+/**
+ * Insert parameters.
+ *
+ * Immutable.
+ */
+class Insert implements Query
+{
+    use BaseTrait;
+
+    /**
+     * @param array<string, mixed> $params
+     */
+    private function validateRawParams(array $params): void
+    {
+        $into = $params['into'] ?? null;
+
+        if (!$into || !is_string($into)) {
+            throw new RuntimeException("Bad or missing 'into' parameter.");
+        }
+
+        $columns = $params['columns'] ?? [];
+
+        if (!is_array($columns)) {
+            throw new RuntimeException("Bad 'columns' parameter.");
+        }
+
+        $values = $params['values'] ?? [];
+
+        if (!is_array($values)) {
+            throw new RuntimeException("Bad 'values' parameter.");
+        }
+
+        $updateSet = $params['updateSet'] ?? null;
+
+        if ($updateSet && !is_array($updateSet)) {
+            throw new RuntimeException("Bad 'updateSet' parameter.");
+        }
+    }
+}

application/Espo/ORM/Query/InsertBuilder.php

@@ -0,0 +1,122 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+class InsertBuilder implements Builder
+{
+    use BaseBuilderTrait;
+
+    /**
+     * @var array<string, mixed>
+     */
+    protected $params = [];
+
+    /**
+     * Create an instance.
+     */
+    public static function create(): self
+    {
+        return new self();
+    }
+
+    /**
+     * Build a INSERT query.
+     */
+    public function build(): Insert
+    {
+        return Insert::fromRaw($this->params);
+    }
+
+    /**
+     * Clone an existing query for a subsequent modifying and building.
+     */
+    public function clone(Insert $query): self
+    {
+        $this->cloneInternal($query);
+
+        return $this;
+    }
+
+    /**
+     * Into what entity type to insert.
+     */
+    public function into(string $entityType): self
+    {
+        $this->params['into'] = $entityType;
+
+        return $this;
+    }
+
+    /**
+     * What columns to set with values. A list of columns.
+     *
+     * @param string[] $columns
+     */
+    public function columns(array $columns): self
+    {
+        $this->params['columns'] = $columns;
+
+        return $this;
+    }
+
+    /**
+     * What values to insert. A key-value map or a list of key-value maps.
+     *
+     * @param array<string, ?scalar>|array<string, ?scalar>[] $values
+     */
+    public function values(array $values): self
+    {
+        $this->params['values'] = $values;
+
+        return $this;
+    }
+
+    /**
+     * Values to set on duplicate key. A key-value map.
+     *
+     * @param array<string, ?scalar> $updateSet
+     */
+    public function updateSet(array $updateSet): self
+    {
+        $this->params['updateSet'] = $updateSet;
+
+        return $this;
+    }
+
+    /**
+     * For a mass insert by a select sub-query.
+     */
+    public function valuesQuery(SelectingQuery $query): self
+    {
+        $this->params['valuesQuery'] = $query;
+
+        return $this;
+    }
+}

application/Espo/ORM/Query/LockTable.php

@@ -0,0 +1,59 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use RuntimeException;
+
+/**
+ * LOCK TABLE parameters.
+ *
+ * Immutable.
+ */
+class LockTable implements Query
+{
+    use BaseTrait;
+
+    public const MODE_SHARE = 'SHARE';
+    public const MODE_EXCLUSIVE = 'EXCLUSIVE';
+
+    /**
+     * @param array<string, mixed> $params
+     */
+    protected function validateRawParams(array $params): void
+    {
+        if (empty($params['table'])) {
+            throw new RuntimeException("LockTable params: No table specified.");
+        }
+
+        if (empty($params['mode'])) {
+            throw new RuntimeException("LockTable params: No mode specified.");
+        }
+    }
+}

application/Espo/ORM/Query/LockTableBuilder.php

@@ -0,0 +1,91 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+class LockTableBuilder implements Builder
+{
+    use BaseBuilderTrait;
+
+    /**
+     * Create an instance.
+     */
+    public static function create(): self
+    {
+        return new self();
+    }
+
+    /**
+     * Build a LOCK TABLE query.
+     */
+    public function build(): LockTable
+    {
+        return LockTable::fromRaw($this->params);
+    }
+
+    /**
+     * Clone an existing query for a subsequent modifying and building.
+     */
+    public function clone(LockTable $query): self
+    {
+        $this->cloneInternal($query);
+
+        return $this;
+    }
+
+    /**
+     * What entity type to lock.
+     */
+    public function table(string $entityType): self
+    {
+        $this->params['table'] = $entityType;
+
+        return $this;
+    }
+
+    /**
+     * In SHARE mode.
+     */
+    public function inShareMode(): self
+    {
+        $this->params['mode'] = LockTable::MODE_SHARE;
+
+        return $this;
+    }
+
+    /**
+     * In EXCLUSIVE mode.
+     */
+    public function inExclusiveMode(): self
+    {
+        $this->params['mode'] = LockTable::MODE_EXCLUSIVE;
+
+        return $this;
+    }
+}

application/Espo/ORM/Query/Part/Condition.php

@@ -0,0 +1,217 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part;
+
+use Espo\ORM\Query\Part\Where\AndGroup;
+use Espo\ORM\Query\Part\Where\Comparison;
+use Espo\ORM\Query\Part\Where\Exists;
+use Espo\ORM\Query\Part\Where\Not;
+use Espo\ORM\Query\Part\Where\OrGroup;
+
+use Espo\ORM\Query\Select;
+
+/**
+ * A util-class for creating items that can be used as a where-clause.
+ */
+class Condition
+{
+    private function __construct()
+    {}
+
+    /**
+     * Create 'AND' group.
+     */
+    public static function and(WhereItem ...$items): AndGroup
+    {
+        return AndGroup::create(...$items);
+    }
+
+    /**
+     * Create 'OR' group.
+     */
+    public static function or(WhereItem ...$items): OrGroup
+    {
+        return OrGroup::create(...$items);
+    }
+
+    /**
+     * Create 'NOT'.
+     */
+    public static function not(WhereItem $item): Not
+    {
+        return Not::create($item);
+    }
+
+    /**
+     * Create `EXISTS`.
+     */
+    public static function exists(Select $subQuery): Exists
+    {
+        return Exists::create($subQuery);
+    }
+
+    /**
+     * Create a column reference expression.
+     *
+     * @param string $expression Examples: `columnName`, `alias.columnName`.
+     */
+    public static function column(string $expression): Expression
+    {
+        return Expression::column($expression);
+    }
+
+    /**
+     * Create '=' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float|bool|null $argument2 A scalar, expression or sub-query.
+     */
+    public static function equal(
+        Expression $argument1,
+        Expression|Select|string|int|float|bool|null $argument2
+    ): Comparison {
+
+        return Comparison::equal($argument1, $argument2);
+    }
+
+    /**
+     * Create '!=' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float|bool|null $argument2 A scalar, expression or sub-query.
+     */
+    public static function notEqual(
+        Expression $argument1,
+        Expression|Select|string|int|float|bool|null $argument2
+    ): Comparison {
+
+        return Comparison::notEqual($argument1, $argument2);
+    }
+
+    /**
+     * Create 'LIKE' comparison.
+     *
+     * @param Expression $subject What to test.
+     * @param Expression|string $pattern A pattern.
+     */
+    public static function like(Expression $subject, Expression|string $pattern): Comparison
+    {
+        return Comparison::like($subject, $pattern);
+    }
+
+    /**
+     * Create 'NOT LIKE' comparison.
+     *
+     * @param Expression $subject What to test.
+     * @param Expression|string $pattern A pattern.
+     */
+    public static function notLike(Expression $subject, Expression|string $pattern): Comparison
+    {
+        return Comparison::notLike($subject, $pattern);
+    }
+
+    /**
+     * Create '>' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float $argument2 A scalar, expression or sub-query.
+     */
+    public static function greater(
+        Expression $argument1,
+        Expression|Select|string|int|float $argument2
+    ): Comparison {
+
+        return Comparison::greater($argument1, $argument2);
+    }
+
+    /**
+     * Create '>=' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float $argument2 A scalar, expression or sub-query.
+     */
+    public static function greaterOrEqual(
+        Expression $argument1,
+        Expression|Select|string|int|float $argument2
+    ): Comparison {
+
+        return Comparison::greaterOrEqual($argument1, $argument2);
+    }
+
+    /**
+     * Create '<' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float $argument2 A scalar, expression or sub-query.
+     */
+    public static function less(
+        Expression $argument1,
+        Expression|Select|string|int|float $argument2
+    ): Comparison {
+
+        return Comparison::less($argument1, $argument2);
+    }
+
+    /**
+     * Create '<=' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float $argument2 A scalar, expression or sub-query.
+     */
+    public static function lessOrEqual(
+        Expression $argument1,
+        Expression|Select|string|int|float $argument2
+    ): Comparison {
+
+        return Comparison::lessOrEqual($argument1, $argument2);
+    }
+
+    /**
+     * Create 'IN' comparison.
+     *
+     * @param Expression $subject What to test.
+     * @param Select|scalar[] $set A set of values. A select query or array of scalars.
+     */
+    public static function in(Expression $subject, Select|array $set): Comparison
+    {
+        return Comparison::in($subject, $set);
+    }
+
+    /**
+     * Create 'NOT IN' comparison.
+     *
+     * @param Expression $subject What to test.
+     * @param Select|scalar[] $set A set of values. A select query or array of scalars.
+     */
+    public static function notIn(Expression $subject, Select|array $set): Comparison
+    {
+        return Comparison::notIn($subject, $set);
+    }
+}

application/Espo/ORM/Query/Part/Expression.php

@@ -0,0 +1,820 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part;
+
+use Espo\ORM\Query\Part\Expression\Util;
+
+use RuntimeException;
+
+/**
+ * A complex expression. Can be a function or a simple column reference. Immutable.
+ */
+class Expression implements WhereItem
+{
+    private string $expression;
+
+    public function __construct(string $expression)
+    {
+        if ($expression === '') {
+            throw new RuntimeException("Expression can't be empty.");
+        }
+
+        if (str_ends_with($expression, ':')) {
+            throw new RuntimeException("Expression should not end with `:`.");
+        }
+
+        $this->expression = $expression;
+    }
+
+    public function getRaw(): array
+    {
+        return [$this->getRawKey() => null];
+    }
+
+    public function getRawKey(): string
+    {
+        return $this->expression . ':';
+    }
+
+    public function getRawValue(): mixed
+    {
+        return null;
+    }
+
+    /**
+     * Get a string expression.
+     */
+    public function getValue(): string
+    {
+        return $this->expression;
+    }
+
+    /**
+     * Create an expression from a string.
+     */
+    public static function create(string $expression): self
+    {
+        return new self($expression);
+    }
+
+    /**
+     * Create an expression from a scalar value or NULL.
+     *
+     * @param string|float|int|bool|null $value A scalar or NULL.
+     */
+    public static function value(string|float|int|bool|null $value): self
+    {
+        return self::create(self::stringifyArgument($value));
+    }
+
+    /**
+     * Create a column reference expression.
+     *
+     * @param string $expression Examples: `columnName`, `alias.columnName`.
+     */
+    public static function column(string $expression): self
+    {
+        $string = $expression;
+
+        if (strlen($string) && $string[0] === '@') {
+            $string = substr($string, 1);
+        }
+
+        if ($string === '') {
+            throw new RuntimeException("Empty column.");
+        }
+
+        if (!preg_match('/^[a-zA-Z\d.]+$/', $string)) {
+            throw new RuntimeException("Bad column. Must be of letters, digits. Can have a dot.");
+        }
+
+        return self::create($expression);
+    }
+
+    /**
+     * Create an alias reference expression.
+     *
+     * @param string $expression Examples: `someAlias`, `subQueryAlias.someAlias`.
+     * @since 8.1.0
+     */
+    public static function alias(string $expression): self
+    {
+        if ($expression === '') {
+            throw new RuntimeException("Empty alias.");
+        }
+
+        if (!preg_match('/^[a-zA-Z\d.]+$/', $expression)) {
+            throw new RuntimeException("Bad alias expression. Must be of letters, digits. Can have a dot.");
+        }
+
+        if (str_contains($expression, '.')) {
+            [$left, $right] = explode('.', $expression, 2);
+
+            return self::create($left . '.#' . $right);
+        }
+
+        return self::create('#' . $expression);
+    }
+
+    /**
+     * 'COUNT' function.
+     *
+     * @param Expression $expression
+     */
+    public static function count(Expression $expression): self
+    {
+        return self::composeFunction('COUNT', $expression);
+    }
+
+    /**
+     * 'MIN' function.
+     *
+     * @param Expression $expression
+     */
+    public static function min(Expression $expression): self
+    {
+        return self::composeFunction('MIN', $expression);
+    }
+
+    /**
+     * 'MAX' function.
+     *
+     * @param Expression $expression
+     */
+    public static function max(Expression $expression): self
+    {
+        return self::composeFunction('MAX', $expression);
+    }
+
+    /**
+     * 'SUM' function.
+     *
+     * @param Expression $expression
+     */
+    public static function sum(Expression $expression): self
+    {
+        return self::composeFunction('SUM', $expression);
+    }
+
+    /**
+     * 'AVG' function.
+     *
+     * @param Expression $expression
+     */
+    public static function average(Expression $expression): self
+    {
+        return self::composeFunction('AVG', $expression);
+    }
+
+    /**
+     * 'IF' function. Return $then if a condition is true, $else otherwise.
+     *
+     * @param Expression $condition A condition.
+     * @param Expression|string|int|float|bool|null $then Then.
+     * @param Expression|string|int|float|bool|null $else Else.
+     */
+    public static function if(
+        Expression $condition,
+        Expression|string|int|float|bool|null $then,
+        Expression|string|int|float|bool|null $else
+    ): self {
+
+        return self::composeFunction('IF', $condition, $then, $else);
+    }
+
+    /**
+     * 'CASE' expression. Even arguments define 'WHEN' conditions, following odd arguments
+     * define 'THEN' values. The last unmatched argument defines the 'ELSE' value.
+     *
+     * @param Expression|scalar|null ...$arguments Arguments.
+     */
+    public static function switch(Expression|string|int|float|bool|null ...$arguments): self
+    {
+        if (count($arguments) < 2) {
+            throw new RuntimeException("Too few arguments.");
+        }
+
+        return self::composeFunction('SWITCH', ...$arguments);
+    }
+
+    /**
+     * 'CASE' expression that maps keys to values. The first argument is the value to map.
+     * Odd arguments define keys, the following even arguments define mapped values.
+     * The last unmatched argument defines the 'ELSE' value.
+     *
+     * @param Expression|scalar|null ...$arguments Arguments.
+     */
+    public static function map(Expression|string|int|float|bool|null ...$arguments): self
+    {
+        if (count($arguments) < 3) {
+            throw new RuntimeException("Too few arguments.");
+        }
+
+        return self::composeFunction('MAP', ...$arguments);
+    }
+
+    /**
+     * 'IFNULL' function. If the first argument is not NULL, returns it,
+     * otherwise returns the second argument.
+     *
+     * @param Expression $value A value.
+     * @param Expression|string|int|float|bool $fallbackValue A fallback value.
+     */
+    public static function ifNull(Expression $value, Expression|string|int|float|bool $fallbackValue): self
+    {
+        return self::composeFunction('IFNULL', $value, $fallbackValue);
+    }
+
+    /**
+     * 'NULLIF' function. If $arg1 = $arg2, returns NULL,
+     * otherwise returns the first argument.
+     *
+     * @param Expression|string|int|float|bool $argument1
+     * @param Expression|string|int|float|bool $argument2
+     */
+    public static function nullIf(
+        Expression|string|int|float|bool $argument1,
+        Expression|string|int|float|bool $argument2
+    ): self {
+
+        return self::composeFunction('NULLIF', $argument1, $argument2);
+    }
+
+    /**
+     * 'LIKE' operator.
+     *
+     * Example: `like(Expression:column('test'), 'test%'`.
+     *
+     * @param Expression $subject A subject.
+     * @param Expression|string $pattern A pattern.
+     */
+    public static function like(Expression $subject, Expression|string $pattern): self
+    {
+        return self::composeFunction('LIKE', $subject, $pattern);
+    }
+
+    /**
+     * '=' operator.
+     *
+     * @param Expression|string|int|float|bool $argument1
+     * @param Expression|string|int|float|bool $argument2
+     */
+    public static function equal(
+        Expression|string|int|float|bool $argument1,
+        Expression|string|int|float|bool $argument2
+    ): self {
+
+        return self::composeFunction('EQUAL', $argument1, $argument2);
+    }
+
+    /**
+     * '<>' operator.
+     *
+     * @param Expression|string|int|float|bool $argument1
+     * @param Expression|string|int|float|bool $argument2
+     */
+    public static function notEqual(
+        Expression|string|int|float|bool $argument1,
+        Expression|string|int|float|bool $argument2
+    ): self {
+
+        return self::composeFunction('NOT_EQUAL', $argument1, $argument2);
+    }
+
+    /**
+     * '>' operator.
+     *
+     * @param Expression|string|int|float|bool $argument1
+     * @param Expression|string|int|float|bool $argument2
+     */
+    public static function greater(
+        Expression|string|int|float|bool $argument1,
+        Expression|string|int|float|bool $argument2
+    ): self {
+
+        return self::composeFunction('GREATER_THAN', $argument1, $argument2);
+    }
+
+    /**
+     * '<' operator.
+     *
+     * @param Expression|string|int|float|bool $argument1
+     * @param Expression|string|int|float|bool $argument2
+     */
+    public static function less(
+        Expression|string|int|float|bool $argument1,
+        Expression|string|int|float|bool $argument2
+    ): self {
+
+        return self::composeFunction('LESS_THAN', $argument1, $argument2);
+    }
+
+    /**
+     * '>=' operator.
+     *
+     * @param Expression|string|int|float|bool $argument1
+     * @param Expression|string|int|float|bool $argument2
+     */
+    public static function greaterOrEqual(
+        Expression|string|int|float|bool $argument1,
+        Expression|string|int|float|bool $argument2
+    ): self {
+
+        return self::composeFunction('GREATER_THAN_OR_EQUAL', $argument1, $argument2);
+    }
+
+    /**
+     * '<=' operator.
+     *
+     * @param Expression|string|int|float|bool $argument1
+     * @param Expression|string|int|float|bool $argument2
+     */
+    public static function lessOrEqual(
+        Expression|string|int|float|bool $argument1,
+        Expression|string|int|float|bool $argument2
+    ): self {
+
+        return self::composeFunction('LESS_THAN_OR_EQUAL', $argument1, $argument2);
+    }
+
+    /**
+     * 'IS NULL' operator.
+     *
+     * @param Expression $expression
+     */
+    public static function isNull(Expression $expression): self
+    {
+        return self::composeFunction('IS_NULL', $expression);
+    }
+
+    /**
+     * 'IS NOT NULL' operator.
+     *
+     * @param Expression $expression
+     */
+    public static function isNotNull(Expression $expression): self
+    {
+        return self::composeFunction('IS_NOT_NULL', $expression);
+    }
+
+    /**
+     * 'IN' operator. Check whether a value is within a set of values.
+     *
+     * @param Expression $expression
+     * @param Expression[]|string[]|int[]|float[]|bool[] $values
+     */
+    public static function in(Expression $expression, array $values): self
+    {
+        return self::composeFunction('IN', $expression, ...$values);
+    }
+
+    /**
+     * 'NOT IN' operator. Check whether a value is not within a set of values.
+     *
+     * @param Expression $expression
+     * @param Expression[]|string[]|int[]|float[]|bool[] $values
+     */
+    public static function notIn(Expression $expression, array $values): self
+    {
+        return self::composeFunction('NOT_IN', $expression, ...$values);
+    }
+
+    /**
+     * 'COALESCE' function. Returns the first non-NULL value in the list.
+     */
+    public static function coalesce(Expression ...$expressions): self
+    {
+        return self::composeFunction('COALESCE', ...$expressions);
+    }
+
+    /**
+     * 'MONTH' function. Returns a month number of a passed date or date-time.
+     *
+     * @param Expression $date
+     */
+    public static function month(Expression $date): self
+    {
+        return self::composeFunction('MONTH_NUMBER', $date);
+    }
+
+    /**
+     * 'WEEK' function. Returns a week number of a passed date or date-time.
+     *
+     * @param Expression $date
+     * @param int $weekStart A week start. `0` for Sunday, `1` for Monday.
+     */
+    public static function week(Expression $date, int $weekStart = 0): self
+    {
+        if ($weekStart !== 0 && $weekStart !== 1) {
+            throw new RuntimeException("Week start can be only 0 or 1.");
+        }
+
+        if ($weekStart === 1) {
+            return self::composeFunction('WEEK_NUMBER_1', $date);
+        }
+
+        return self::composeFunction('WEEK_NUMBER', $date);
+    }
+
+    /**
+     * 'DAYOFWEEK' function. A day of week of a passed date or date-time. 1..7.
+     *
+     * @param Expression $date
+     */
+    public static function dayOfWeek(Expression $date): self
+    {
+        return self::composeFunction('DAYOFWEEK', $date);
+    }
+
+    /**
+     * 'DAYOFMONTH' function. A day of month of a passed date or date-time. 1..31.
+     *
+     * @param Expression $date
+     */
+    public static function dayOfMonth(Expression $date): self
+    {
+        return self::composeFunction('DAYOFMONTH', $date);
+    }
+
+    /**
+     * 'YEAR' function. A year number of a passed date or date-time.
+     *
+     * @param Expression $date
+     */
+    public static function year(Expression $date): self
+    {
+        return self::composeFunction('YEAR', $date);
+    }
+
+    /**
+     * 'YEAR' function taking into account a fiscal year start.
+     *
+     * @param Expression $date
+     * @param int $fiscalYearStart A month number of a fiscal year start. 1..12.
+     */
+    public static function yearFiscal(Expression $date, int $fiscalYearStart = 1): self
+    {
+        if ($fiscalYearStart < 1 || $fiscalYearStart > 12) {
+            throw new RuntimeException("Bad fiscal year start.");
+        }
+
+        return self::composeFunction('YEAR_' . strval($fiscalYearStart), $date);
+    }
+
+    /**
+     * 'QUARTER' function. A quarter number of a passed date or date-time. 1..4.
+     *
+     * @param Expression $date
+     */
+    public static function quarter(Expression $date): self
+    {
+        return self::composeFunction('QUARTER_NUMBER', $date);
+    }
+
+    /**
+     * 'HOUR' function. A hour number of a passed date-time. 0..23.
+     *
+     * @param Expression $dateTime
+     */
+    public static function hour(Expression $dateTime): self
+    {
+        return self::composeFunction('HOUR', $dateTime);
+    }
+
+    /**
+     * 'MINUTE' function. A minute number of a passed date-time. 0..59.
+     *
+     * @param Expression $dateTime
+     */
+    public static function minute(Expression $dateTime): self
+    {
+        return self::composeFunction('MINUTE', $dateTime);
+    }
+
+    /**
+     * 'SECOND' function. A second number of a passed date-time. 0..59.
+     *
+     * @param Expression $dateTime
+     */
+    public static function second(Expression $dateTime): self
+    {
+        return self::composeFunction('SECOND', $dateTime);
+    }
+
+    /**
+     * 'UNIX_TIMESTAMP' function. Seconds.
+     *
+     * @param Expression $dateTime
+     * @since 9.0.0
+     */
+    public static function unixTimestamp(Expression $dateTime): self
+    {
+        return self::composeFunction('UNIX_TIMESTAMP', $dateTime);
+    }
+
+    /**
+     * 'NOW' function. A current date and time.
+     */
+    public static function now(): self
+    {
+        return self::composeFunction('NOW');
+    }
+
+    /**
+     * 'DATE' function. Returns a date part of a date-time.
+     *
+     * @param Expression $dateTime
+     */
+    public static function date(Expression $dateTime): self
+    {
+        return self::composeFunction('DATE', $dateTime);
+    }
+
+    /**
+     * Time zone conversion function. Converts a passed data-time applying a hour offset.
+     *
+     * @param Expression $date
+     */
+    public static function convertTimezone(Expression $date, float $offset): self
+    {
+        return self::composeFunction('TZ', $date, $offset);
+    }
+
+    /**
+     * 'CONCAT' function. Concatenates multiple strings.
+     *
+     * @param Expression|string ...$strings Strings.
+     */
+    public static function concat(Expression|string ...$strings): self
+    {
+        return self::composeFunction('CONCAT', ...$strings);
+    }
+
+    /**
+     * 'LEFT' function. Returns a specified number of characters from the left of a string.
+     */
+    public static function left(Expression $string, int $offset): self
+    {
+        return self::composeFunction('LEFT', $string, $offset);
+    }
+
+    /**
+     * 'LOWER' function. Converts a string to a lower case.
+     */
+    public static function lowerCase(Expression $string): self
+    {
+        return self::composeFunction('LOWER', $string);
+    }
+
+    /**
+     * 'UPPER' function. Converts a string to an upper case.
+     */
+    public static function upperCase(Expression $string): self
+    {
+        return self::composeFunction('UPPER', $string);
+    }
+
+    /**
+     * 'TRIM' function. Removes leading and trailing spaces.
+     */
+    public static function trim(Expression $string): self
+    {
+        return self::composeFunction('TRIM', $string);
+    }
+
+    /**
+     * 'BINARY' function. Converts a string value to a binary string.
+     */
+    public static function binary(Expression $string): self
+    {
+        return self::composeFunction('BINARY', $string);
+    }
+
+    /**
+     * 'CHAR_LENGTH' function. A number of characters in a string.
+     */
+    public static function charLength(Expression $string): self
+    {
+        return self::composeFunction('CHAR_LENGTH', $string);
+    }
+
+    /**
+     * 'REPLACE' function. Replaces all the occurrences of a sub-string within a string.
+     *
+     * @param Expression $haystack A subject.
+     * @param Expression|string $needle A string to be replaced.
+     * @param Expression|string $replaceWith A string to replace with.
+     */
+    public static function replace(
+        Expression $haystack,
+        Expression|string $needle,
+        Expression|string $replaceWith
+    ): self {
+
+        return self::composeFunction('REPLACE', $haystack, $needle, $replaceWith);
+    }
+
+    /**
+     * 'FIELD' operator (in MySQL). Returns an index (position) of an expression
+     * in a list. Returns `0` if not found. The first index is `1`.
+     *
+     * @param Expression $expression
+     * @param Expression[]|string[]|int[]|float[] $list
+     */
+    public static function positionInList(Expression $expression, array $list): self
+    {
+        return self::composeFunction('POSITION_IN_LIST', $expression, ...$list);
+    }
+
+    /**
+     * 'ADD' function. Adds two or more numbers.
+     *
+     * @param Expression|int|float ...$arguments
+     */
+    public static function add(Expression|int|float ...$arguments): self
+    {
+        if (count($arguments) < 2) {
+            throw new RuntimeException("Too few arguments.");
+        }
+
+        return self::composeFunction('ADD', ...$arguments);
+    }
+
+    /**
+     * 'SUB' function. Subtraction.
+     *
+     * @param Expression|int|float ...$arguments
+     */
+    public static function subtract(Expression|int|float ...$arguments): self
+    {
+        if (count($arguments) < 2) {
+            throw new RuntimeException("Too few arguments.");
+        }
+
+        return self::composeFunction('SUB', ...$arguments);
+    }
+
+    /**
+     * 'MUL' function. Multiplication.
+     *
+     * @param Expression|int|float ...$arguments
+     */
+    public static function multiply(Expression|int|float ...$arguments): self
+    {
+        if (count($arguments) < 2) {
+            throw new RuntimeException("Too few arguments.");
+        }
+
+        return self::composeFunction('MUL', ...$arguments);
+    }
+
+    /**
+     * 'DIV' function. Division.
+     *
+     * @param Expression|int|float ...$arguments
+     */
+    public static function divide(Expression|int|float ...$arguments): self
+    {
+        if (count($arguments) < 2) {
+            throw new RuntimeException("Too few arguments.");
+        }
+
+        return self::composeFunction('DIV', ...$arguments);
+    }
+
+    /**
+     * 'MOD' function. Returns a remainder of a number divided by another number.
+     *
+     * @param Expression|int|float ...$arguments
+     */
+    public static function modulo(Expression|int|float ...$arguments): self
+    {
+        if (count($arguments) < 2) {
+            throw new RuntimeException("Too few arguments.");
+        }
+
+        return self::composeFunction('MOD', ...$arguments);
+    }
+
+    /**
+     * 'FLOOR' function. The largest integer value not greater than the argument.
+     */
+    public static function floor(Expression $number): self
+    {
+        return self::composeFunction('FLOOR', $number);
+    }
+
+    /**
+     * 'CEIL' function. The largest integer value not greater than the argument.
+     */
+    public static function ceil(Expression $number): self
+    {
+        return self::composeFunction('CEIL', $number);
+    }
+
+    /**
+     * 'ROUND' function. Rounds a number to a specified number of decimal places.
+     */
+    public static function round(Expression $number, int $precision = 0): self
+    {
+        return self::composeFunction('ROUND', $number, $precision);
+    }
+
+    /**
+     * 'GREATEST' function. A max value from a list of expressions.
+     */
+    public static function greatest(Expression ...$arguments): self
+    {
+        return self::composeFunction('GREATEST', ...$arguments);
+    }
+
+    /**
+     * 'LEAST' function. A min value from a list of expressions.
+     */
+    public static function least(Expression ...$arguments): self
+    {
+        return self::composeFunction('LEAST', ...$arguments);
+    }
+
+    /**
+     * 'ANY_VALUE' function.
+     *
+     * @since 9.1.6
+     */
+    public function anyValue(Expression $expression): self
+    {
+        return self::composeFunction('ANY_VALUE', $expression);
+    }
+
+    /**
+     * 'AND' operator. Returns TRUE if all arguments are TRUE.
+     */
+    public static function and(Expression ...$arguments): self
+    {
+        return self::composeFunction('AND', ...$arguments);
+    }
+
+    /**
+     * 'OR' operator. Returns TRUE if at least one argument is TRUE.
+     */
+    public static function or(Expression ...$arguments): self
+    {
+        return self::composeFunction('OR', ...$arguments);
+    }
+
+    /**
+     * 'NOT' operator. Negates an expression.
+     */
+    public static function not(Expression $argument): self
+    {
+        return self::composeFunction('NOT', $argument);
+    }
+
+    /**
+     * 'ROW' constructor.
+     */
+    public static function row(Expression ...$arguments): self
+    {
+        return self::composeFunction('ROW', ...$arguments);
+    }
+
+    private static function composeFunction(
+        string $function,
+        Expression|bool|int|float|string|null ...$arguments
+    ): self {
+
+        return Util::composeFunction($function, ...$arguments);
+    }
+
+    private static function stringifyArgument(Expression|bool|int|float|string|null $argument): string
+    {
+        return Util::stringifyArgument($argument);
+    }
+}

application/Espo/ORM/Query/Part/Expression/Util.php

@@ -0,0 +1,88 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part\Expression;
+
+use Espo\ORM\Query\Part\Expression;
+
+class Util
+{
+    /**
+     * Compose an expression by a function name and arguments.
+     *
+     * @param Expression|bool|int|float|string|null ...$arguments Arguments
+     */
+    public static function composeFunction(
+        string $function,
+        Expression|bool|int|float|string|null ...$arguments
+    ): Expression {
+
+        $stringifiedItems = array_map(
+            function ($item) {
+                return self::stringifyArgument($item);
+            },
+            $arguments
+        );
+
+        $expression = $function . ':(' . implode(', ', $stringifiedItems) . ')';
+
+        return Expression::create($expression);
+    }
+
+    /**
+     * Stringify an argument.
+     *
+     * @param Expression|bool|int|float|string|null $argument
+     */
+    public static function stringifyArgument(Expression|bool|int|float|string|null $argument): string
+    {
+
+        if ($argument instanceof Expression) {
+            return $argument->getValue();
+        }
+
+        if (is_null($argument)) {
+            return 'NULL';
+        }
+
+       if (is_bool($argument)) {
+            return $argument ? 'TRUE': 'FALSE';
+        }
+
+       if (is_int($argument)) {
+           return strval($argument);
+       }
+
+       if (is_float($argument)) {
+           return strval($argument);
+       }
+
+       return '\'' . str_replace('\'', '\\\'', $argument) . '\'';
+    }
+}

application/Espo/ORM/Query/Part/Join.php

@@ -0,0 +1,300 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part;
+
+use Espo\ORM\Query\Part\Join\JoinType;
+use Espo\ORM\Query\Select;
+use LogicException;
+use RuntimeException;
+
+/**
+ * A join item. Immutable.
+ */
+class Join
+{
+    /** A table join. */
+    public const MODE_TABLE = 0;
+    /** A relation join. */
+    public const MODE_RELATION = 1;
+    /** A sub-query join. */
+    public const MODE_SUB_QUERY = 3;
+
+    private ?WhereItem $conditions = null;
+    private bool $onlyMiddle = false;
+    private bool $isLateral = false;
+    private ?JoinType $type = null;
+
+    private function __construct(
+        private string|Select $target,
+        private ?string $alias = null
+    ) {
+        if ($target === '' || $alias === '') {
+            throw new RuntimeException("Bad join.");
+        }
+    }
+
+    /**
+     * Get a join target. A relation name, table or sub-query.
+     * A relation name is in camelCase, a table is in CamelCase.
+     */
+    public function getTarget(): string|Select
+    {
+        return $this->target;
+    }
+
+    /**
+     * Get an alias.
+     */
+    public function getAlias(): ?string
+    {
+        return $this->alias;
+    }
+
+    /**
+     * Get join conditions.
+     */
+    public function getConditions(): ?WhereItem
+    {
+        return $this->conditions;
+    }
+
+    /**
+     * Is a sub-query join.
+     */
+    public function isSubQuery(): bool
+    {
+        return !is_string($this->target);
+    }
+
+    /**
+     * Is a table join.
+     */
+    public function isTable(): bool
+    {
+        return is_string($this->target) && $this->target[0] === ucfirst($this->target[0]);
+    }
+
+    /**
+     * Is a relation join.
+     */
+    public function isRelation(): bool
+    {
+        return !$this->isSubQuery() && !$this->isTable();
+    }
+
+    /**
+     * Get a join mode.
+     *
+     * @return self::MODE_TABLE|self::MODE_RELATION|self::MODE_SUB_QUERY
+     */
+    public function getMode(): int
+    {
+        if ($this->isSubQuery()) {
+            return self::MODE_SUB_QUERY;
+        }
+
+        if ($this->isRelation()) {
+            return self::MODE_RELATION;
+        }
+
+        return self::MODE_TABLE;
+    }
+
+    /**
+     * Is only middle table to be joined.
+     */
+    public function isOnlyMiddle(): bool
+    {
+        return $this->onlyMiddle;
+    }
+
+    /**
+     * Is LATERAL.
+     *
+     * @since 9.1.6
+     */
+    public function isLateral(): bool
+    {
+        return $this->isLateral;
+    }
+
+    /**
+     * Get a join type.
+     *
+     * @return JoinType|null
+     *
+     * @since 9.2.0
+     */
+    public function getType(): ?JoinType
+    {
+        return $this->type;
+    }
+
+    /**
+     * Create.
+     *
+     * @param string|Select $target
+     * A relation name, table or sub-query. A relation name should be in camelCase, a table in CamelCase.
+     * When joining a table or sub-query, conditions should be specified.
+     * When joining a relation, conditions will be applied automatically, additional conditions can
+     * be specified as well.
+     * @param ?string $alias An alias.
+     */
+    public static function create(string|Select $target, ?string $alias = null): self
+    {
+        return new self($target, $alias);
+    }
+
+    /**
+     * Create with a table target.
+     *
+     * @param string $table A table name. Should start with an upper case letter.
+     * @param ?string $alias An alias.
+     */
+    public static function createWithTableTarget(string $table, ?string $alias = null): self
+    {
+        return self::create(ucfirst($table), $alias);
+    }
+
+    /**
+     * Create with a relation target. Conditions will be applied automatically.
+     *
+     * @param string $relation A relation name. Should start with a lower case letter.
+     * @param ?string $alias An alias.
+     */
+    public static function createWithRelationTarget(string $relation, ?string $alias = null): self
+    {
+        return self::create(lcfirst($relation), $alias);
+    }
+
+    /**
+     * Create with a sub-query.
+     *
+     * @param Select $subQuery A sub-query.
+     * @param string $alias An alias.
+     */
+    public static function createWithSubQuery(Select $subQuery, string $alias): self
+    {
+        return new self($subQuery, $alias);
+    }
+
+    /**
+     * Clone with an alias.
+     */
+    public function withAlias(?string $alias): self
+    {
+        $obj = clone $this;
+        $obj->alias = $alias;
+
+        return $obj;
+    }
+
+    /**
+     * Clone with join conditions.
+     */
+    public function withConditions(?WhereItem $conditions): self
+    {
+        $obj = clone $this;
+        $obj->conditions = $conditions;
+
+        return $obj;
+    }
+
+    /**
+     * Join only middle table. For many-to-many relationships.
+     */
+    public function withOnlyMiddle(bool $onlyMiddle = true): self
+    {
+        if (!$this->isRelation()) {
+            throw new LogicException("Only-middle is compatible only with relation joins.");
+        }
+
+        $obj = clone $this;
+        $obj->onlyMiddle = $onlyMiddle;
+
+        return $obj;
+    }
+
+    /**
+     * With LATERAL. Only for a sub-query join.
+     *
+     * @since 9.1.6
+     */
+    public function withLateral(bool $isLateral = true): self
+    {
+        if (!$this->isSubQuery()) {
+            throw new LogicException("Lateral can be used only with sub-query joins.");
+        }
+
+        $obj = clone $this;
+        $obj->isLateral = $isLateral;
+
+        return $obj;
+    }
+
+    /**
+     * With LEFT type.
+     *
+     * @since 9.2.0.
+     */
+    public function withLeft(): self
+    {
+        $obj = clone $this;
+        $obj->type = JoinType::left;
+
+        return $obj;
+    }
+
+    /**
+     * With INNER type.
+     *
+     * @since 9.2.0.
+     */
+    public function withInner(): self
+    {
+        $obj = clone $this;
+        $obj->type = JoinType::inner;
+
+        return $obj;
+    }
+
+    /**
+     * With a join type.
+     *
+     * @since 9.2.0.
+     */
+    public function withType(JoinType $type): self
+    {
+        $obj = clone $this;
+        $obj->type = $type;
+
+        return $obj;
+    }
+}

application/Espo/ORM/Query/Part/Join/JoinType.php

@@ -0,0 +1,46 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part\Join;
+
+/**
+ * @since 9.2.0
+ */
+enum JoinType: string
+{
+    /**
+     * An INNER join.
+     */
+    case inner = 'inner';
+
+    /**
+     * A LEFT join.
+     */
+    case left = 'left';
+}

application/Espo/ORM/Query/Part/Order.php

@@ -0,0 +1,156 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part;
+
+use RuntimeException;
+
+/**
+ * An order item. Immutable.
+ *
+ * Immutable.
+ */
+class Order
+{
+    public const ASC = 'ASC';
+    public const DESC = 'DESC';
+
+    private Expression $expression;
+    private bool $isDesc = false;
+
+    private function __construct(Expression $expression)
+    {
+        $this->expression = $expression;
+    }
+
+    /**
+     * Get an expression.
+     */
+    public function getExpression(): Expression
+    {
+        return $this->expression;
+    }
+
+    public function isDesc(): bool
+    {
+        return $this->isDesc;
+    }
+
+    /**
+     * Get a direction.
+     *
+     * @return self::DESC|self::ASC
+     */
+    public function getDirection(): string
+    {
+        return $this->isDesc ? self::DESC : self::ASC;
+    }
+
+    /**
+     * Create.
+     */
+    public static function create(Expression $expression): self
+    {
+        return new self($expression);
+    }
+
+    /**
+     * Create from a string expression.
+     */
+    public static function fromString(string $expression): self
+    {
+        return self::create(
+            Expression::create($expression)
+        );
+    }
+
+    /**
+     * Create an order by position in list.
+     * Note: Reverses the list and applies DESC order.
+     *
+     * @param string[]|int[]|float[] $list
+     */
+    public static function createByPositionInList(Expression $expression, array $list): self
+    {
+        $orderExpression = Expression::positionInList($expression, array_reverse($list));
+
+        return self::create($orderExpression)->withDesc();
+    }
+
+    /**
+     * Clone with an ascending direction.
+     */
+    public function withAsc(): self
+    {
+        $obj = clone $this;
+        $obj->isDesc = false;
+
+        return $obj;
+    }
+
+    /**
+     * Clone with a descending direction.
+     */
+    public function withDesc(): self
+    {
+        $obj = clone $this;
+        $obj->isDesc = true;
+
+        return $obj;
+    }
+
+    /**
+     * Clone with a direction.
+     *
+     * @params self::ASC|self::DESC $direction
+     * @throws RuntimeException
+     */
+    public function withDirection(string $direction): self
+    {
+        $obj = clone $this;
+        $obj->isDesc = strtoupper($direction) === self::DESC;
+
+        if (!in_array(strtoupper($direction), [self::DESC, self::ASC])) {
+            throw new RuntimeException("Bad order direction.");
+        }
+
+        return $obj;
+    }
+
+    /**
+     * Clone with a reverse direction.
+     */
+    public function withReverseDirection(): self
+    {
+        $obj = clone $this;
+        $obj->isDesc = !$this->isDesc;
+
+        return $obj;
+    }
+}

application/Espo/ORM/Query/Part/OrderList.php

@@ -0,0 +1,96 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part;
+
+use InvalidArgumentException;
+use Iterator;
+
+/**
+ * A list of order items.
+ *
+ * Immutable.
+ *
+ * @implements Iterator<Order>
+ */
+class OrderList implements Iterator
+{
+    private int $position = 0;
+    /** @var Order[] */
+    private array $list;
+
+    /**
+     * @param Order[] $list
+     */
+    private function __construct(array $list)
+    {
+        foreach ($list as $item) {
+            if (!$item instanceof Order) {
+                throw new InvalidArgumentException();
+            }
+        }
+
+        $this->list = $list;
+    }
+
+    /**
+     * Create an instance.
+     *
+     * @param Order[] $list
+     */
+    public static function create(array $list): self
+    {
+        return new self($list);
+    }
+
+    public function rewind(): void
+    {
+        $this->position = 0;
+    }
+
+    public function current(): Order
+    {
+        return $this->list[$this->position];
+    }
+
+    public function key(): int
+    {
+        return $this->position;
+    }
+
+    public function next(): void
+    {
+        ++$this->position;
+    }
+
+    public function valid(): bool
+    {
+        return isset($this->list[$this->position]);
+    }
+}

application/Espo/ORM/Query/Part/Selection.php

@@ -0,0 +1,73 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part;
+
+/**
+ * A select item. Immutable.
+ *
+ * Immutable.
+ */
+class Selection
+{
+    private function __construct(
+        private Expression $expression,
+        private ?string $alias = null
+    ) {}
+
+    public function getExpression(): Expression
+    {
+        return $this->expression;
+    }
+
+    public function getAlias(): ?string
+    {
+        return $this->alias;
+    }
+
+    public static function create(Expression $expression, ?string $alias = null): self
+    {
+        return new self($expression, $alias);
+    }
+
+    public static function fromString(string $expression): self
+    {
+        return self::create(
+            Expression::create($expression)
+        );
+    }
+
+    public function withAlias(?string $alias): self
+    {
+        $obj = clone $this;
+        $obj->alias = $alias;
+
+        return $obj;
+    }
+}

application/Espo/ORM/Query/Part/Where/AndGroup.php

@@ -0,0 +1,108 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part\Where;
+
+use Espo\ORM\Query\Part\WhereClause;
+use Espo\ORM\Query\Part\WhereItem;
+
+/**
+ * AND-group. Immutable.
+ */
+class AndGroup implements WhereItem
+{
+    /** @var array<string|int, mixed> */
+    private $rawValue = [];
+
+    /**
+     * @return array<string|int, mixed>
+     */
+    public function getRaw(): array
+    {
+        return ['AND' => $this->getRawValue()];
+    }
+
+    public function getRawKey(): string
+    {
+        return 'AND';
+    }
+
+    /**
+     * @return array<string|int, mixed>
+     */
+    public function getRawValue(): array
+    {
+        return $this->rawValue;
+    }
+
+    /**
+     * Get a number of items.
+     */
+    public function getItemCount(): int
+    {
+        return count($this->rawValue);
+    }
+
+    /**
+     * @param array<string|int, mixed> $whereClause
+     * @return self
+     */
+    public static function fromRaw(array $whereClause): self
+    {
+        if (count($whereClause) === 1 && array_keys($whereClause)[0] === 0) {
+            $whereClause = $whereClause[0];
+        }
+
+        // Do not refactor.
+        $obj = static::class === WhereClause::class ?
+            new WhereClause() :
+            new self();
+
+        /** @phpstan-ignore-next-line */
+        $obj->rawValue = $whereClause;
+
+        return $obj;
+    }
+
+    public static function create(WhereItem ...$itemList): self
+    {
+        $builder = self::createBuilder();
+
+        foreach ($itemList as $item) {
+            $builder->add($item);
+        }
+
+        return $builder->build();
+    }
+
+    public static function createBuilder(): AndGroupBuilder
+    {
+        return new AndGroupBuilder();
+    }
+}

application/Espo/ORM/Query/Part/Where/AndGroupBuilder.php

@@ -0,0 +1,95 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part\Where;
+
+use Espo\ORM\Query\Part\WhereItem;
+
+class AndGroupBuilder
+{
+    /** @var array<string|int, mixed> */
+    private array $raw = [];
+
+    public function build(): AndGroup
+    {
+        return AndGroup::fromRaw($this->raw);
+    }
+
+    public function add(WhereItem $item): self
+    {
+        $key = $item->getRawKey();
+        $value = $item->getRawValue();
+
+        if ($item instanceof AndGroup) {
+            $this->raw = self::normalizeRaw($this->raw);
+
+            $this->raw[] = $item->getRawValue();
+
+            return $this;
+        }
+
+        if (count($this->raw) === 0) {
+            $this->raw[$key] = $value;
+
+            return $this;
+        }
+
+        $this->raw = self::normalizeRaw($this->raw);
+
+        $this->raw[] = [$key => $value];
+
+        return $this;
+    }
+
+    /**
+     * Merge with another AndGroup.
+     */
+    public function merge(AndGroup $andGroup): self
+    {
+        $this->raw = array_merge(
+            self::normalizeRaw($this->raw),
+            self::normalizeRaw($andGroup->getRawValue())
+        );
+
+        return $this;
+    }
+
+    /**
+     * @param array<string|int, mixed> $raw
+     * @return array<string|int, mixed>
+     */
+    private static function normalizeRaw(array $raw): array
+    {
+        if (count($raw) === 1 && array_keys($raw)[0] !== 0) {
+            return [$raw];
+        }
+
+        return $raw;
+    }
+}

application/Espo/ORM/Query/Part/Where/Comparison.php

@@ -0,0 +1,433 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part\Where;
+
+use Espo\ORM\Query\Part\Expression;
+use Espo\ORM\Query\Part\WhereItem;
+use Espo\ORM\Query\Select;
+
+use RuntimeException;
+
+/**
+ * Compares an expression to a value or another expression. Immutable.
+ */
+class Comparison implements WhereItem
+{
+    private const OPERATOR_EQUAL = '=';
+    private const OPERATOR_NOT_EQUAL = '!=';
+    private const OPERATOR_GREATER = '>';
+    private const OPERATOR_GREATER_OR_EQUAL = '>=';
+    private const OPERATOR_LESS = '<';
+    private const OPERATOR_LESS_OR_EQUAL = '<=';
+    private const OPERATOR_LIKE = '*';
+    private const OPERATOR_NOT_LIKE = '!*';
+    private const OPERATOR_IN_SUB_QUERY = '=s';
+    private const OPERATOR_NOT_IN_SUB_QUERY = '!=s';
+    private const OPERATOR_NOT_EQUAL_ANY = '!=any';
+    private const OPERATOR_GREATER_ANY = '>any';
+    private const OPERATOR_GREATER_OR_EQUAL_ANY = '>=any';
+    private const OPERATOR_LESS_ANY = '<any';
+    private const OPERATOR_LESS_OR_EQUAL_ANY = '<=any';
+    private const OPERATOR_EQUAL_ALL = '=all';
+    private const OPERATOR_GREATER_ALL = '>all';
+    private const OPERATOR_GREATER_OR_EQUAL_ALL = '>=all';
+    private const OPERATOR_LESS_ALL = '<all';
+    private const OPERATOR_LESS_OR_EQUAL_ALL = '<=all';
+
+    private string $rawKey;
+    private mixed $rawValue;
+
+    private function __construct(string $rawKey, mixed $rawValue)
+    {
+        $this->rawKey = $rawKey;
+        $this->rawValue = $rawValue;
+    }
+
+    public function getRaw(): array
+    {
+        return [$this->rawKey => $this->rawValue];
+    }
+
+    public function getRawKey(): string
+    {
+        return $this->rawKey;
+    }
+
+    public function getRawValue(): mixed
+    {
+        return $this->rawValue;
+    }
+
+    /**
+     * Create '=' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float|bool|null $argument2 A scalar, expression or sub-query.
+     * @return self
+     */
+    public static function equal(
+        Expression $argument1,
+        Expression|Select|string|int|float|bool|null $argument2
+    ): self {
+
+        return self::createComparison(self::OPERATOR_EQUAL, $argument1, $argument2);
+    }
+
+    /**
+     * Create '!=' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float|bool|null $argument2 A scalar, expression or sub-query.
+     * @return self
+     */
+    public static function notEqual(
+        Expression $argument1,
+        Expression|Select|string|int|float|bool|null $argument2
+    ): self {
+
+        return self::createComparison(self::OPERATOR_NOT_EQUAL, $argument1, $argument2);
+    }
+
+    /**
+     * Create 'LIKE' comparison.
+     *
+     * @param Expression $subject What to test.
+     * @param Expression|string $pattern A pattern.
+     * @return self
+     */
+    public static function like(Expression $subject, Expression|string $pattern): self
+    {
+        return self::createComparison(self::OPERATOR_LIKE, $subject, $pattern);
+    }
+
+    /**
+     * Create 'NOT LIKE' comparison.
+     *
+     * @param Expression $subject What to test.
+     * @param Expression|string $pattern A pattern.
+     * @return self
+     */
+    public static function notLike(Expression $subject, Expression|string $pattern): self
+    {
+        return self::createComparison(self::OPERATOR_NOT_LIKE, $subject, $pattern);
+    }
+
+    /**
+     * Create '>' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float $argument2 A scalar, expression or sub-query.
+     * @return self
+     */
+    public static function greater(Expression $argument1, Expression|Select|string|int|float $argument2): self
+    {
+        return self::createComparison(self::OPERATOR_GREATER, $argument1, $argument2);
+    }
+
+    /**
+     * Create '>=' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float $argument2 A scalar, expression or sub-query.
+     * @return self
+     */
+    public static function greaterOrEqual(Expression $argument1, Expression|Select|string|int|float $argument2): self
+    {
+        return self::createComparison(self::OPERATOR_GREATER_OR_EQUAL, $argument1, $argument2);
+    }
+
+    /**
+     * Create '<' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float $argument2 A scalar, expression or sub-query.
+     * @return self
+     */
+    public static function less(Expression $argument1, Expression|Select|string|int|float $argument2): self
+    {
+        return self::createComparison(self::OPERATOR_LESS, $argument1, $argument2);
+    }
+
+    /**
+     * Create '<=' comparison.
+     *
+     * @param Expression $argument1 An expression.
+     * @param Expression|Select|string|int|float $argument2 A scalar, expression or sub-query.
+     * @return self
+     */
+    public static function lessOrEqual(Expression $argument1, Expression|Select|string|int|float $argument2): self
+    {
+        return self::createComparison(self::OPERATOR_LESS_OR_EQUAL, $argument1, $argument2);
+    }
+
+    /**
+     * Create 'IN' comparison.
+     *
+     * @param Expression $subject What to test.
+     * @param Select|scalar[] $set A set of values. A select query or array of scalars.
+     * @return self
+     */
+    public static function in(Expression $subject, Select|array $set): self
+    {
+        if ($set instanceof Select) {
+            return self::createInOrNotInSubQuery(self::OPERATOR_IN_SUB_QUERY, $subject, $set);
+        }
+
+        return self::createInOrNotInArray(self::OPERATOR_EQUAL, $subject, $set);
+    }
+
+    /**
+     * Create 'NOT IN' comparison.
+     *
+     * @param Expression $subject What to test.
+     * @param Select|scalar[] $set A set of values. A select query or array of scalars.
+     * @return self
+     */
+    public static function notIn(Expression $subject, Select|array $set): self
+    {
+        if ($set instanceof Select) {
+            return self::createInOrNotInSubQuery(self::OPERATOR_NOT_IN_SUB_QUERY, $subject, $set);
+        }
+
+        return self::createInOrNotInArray(self::OPERATOR_NOT_EQUAL, $subject, $set);
+    }
+
+    /**
+     * Create '!= ANY' comparison.
+     *
+     * @param Expression $argument An expression.
+     * @param Select $subQuery A sub-query.
+     * @return self
+     */
+    public static function notEqualAny(Expression $argument, Select $subQuery): self
+    {
+        return self::createComparison(self::OPERATOR_NOT_EQUAL_ANY, $argument, $subQuery);
+    }
+
+    /**
+     * Create '> ANY' comparison.
+     *
+     * @param Expression $argument An expression.
+     * @param Select $subQuery A sub-query.
+     * @return self
+     */
+    public static function greaterAny(Expression $argument, Select $subQuery): self
+    {
+        return self::createComparison(self::OPERATOR_GREATER_ANY, $argument, $subQuery);
+    }
+
+    /**
+     * Create '< ANY' comparison.
+     *
+     * @param Expression $argument An expression.
+     * @param Select $subQuery A sub-query.
+     * @return self
+     */
+    public static function lessAny(Expression $argument, Select $subQuery): self
+    {
+        return self::createComparison(self::OPERATOR_LESS_ANY, $argument, $subQuery);
+    }
+
+    /**
+     * Create '>= ANY' comparison.
+     *
+     * @param Expression $argument An expression.
+     * @param Select $subQuery A sub-query.
+     * @return self
+     */
+    public static function greaterOrEqualAny(Expression $argument, Select $subQuery): self
+    {
+        return self::createComparison(self::OPERATOR_GREATER_OR_EQUAL_ANY, $argument, $subQuery);
+    }
+
+    /**
+     * Create '<= ANY' comparison.
+     *
+     * @param Expression $argument An expression.
+     * @param Select $subQuery A sub-query.
+     * @return self
+     */
+    public static function lessOrEqualAny(Expression $argument, Select $subQuery): self
+    {
+        return self::createComparison(self::OPERATOR_LESS_OR_EQUAL_ANY, $argument, $subQuery);
+    }
+
+    /**
+     * Create '= ALL' comparison.
+     *
+     * @param Expression $argument An expression.
+     * @param Select $subQuery A sub-query.
+     * @return self
+     */
+    public static function equalAll(Expression $argument, Select $subQuery): self
+    {
+        return self::createComparison(self::OPERATOR_EQUAL_ALL, $argument, $subQuery);
+    }
+
+    /**
+     * Create '> ALL' comparison.
+     *
+     * @param Expression $argument An expression.
+     * @param Select $subQuery A sub-query.
+     * @return self
+     */
+    public static function greaterAll(Expression $argument, Select $subQuery): self
+    {
+        return self::createComparison(self::OPERATOR_GREATER_ALL, $argument, $subQuery);
+    }
+
+    /**
+     * Create '< ALL' comparison.
+     *
+     * @param Expression $argument An expression.
+     * @param Select $subQuery A sub-query.
+     * @return self
+     */
+    public static function lessAll(Expression $argument, Select $subQuery): self
+    {
+        return self::createComparison(self::OPERATOR_LESS_ALL, $argument, $subQuery);
+    }
+
+    /**
+     * Create '>= ALL' comparison.
+     *
+     * @param Expression $argument An expression.
+     * @param Select $subQuery A sub-query.
+     * @return self
+     */
+    public static function greaterOrEqualAll(Expression $argument, Select $subQuery): self
+    {
+        return self::createComparison(self::OPERATOR_GREATER_OR_EQUAL_ALL, $argument, $subQuery);
+    }
+
+    /**
+     * Create '<= ALL' comparison.
+     *
+     * @param Expression $argument An expression.
+     * @param Select $subQuery A sub-query.
+     * @return self
+     */
+    public static function lessOrEqualAll(Expression $argument, Select $subQuery): self
+    {
+        return self::createComparison(self::OPERATOR_LESS_OR_EQUAL_ALL, $argument, $subQuery);
+    }
+
+    private static function createComparison(
+        string $operator,
+        Expression|string $argument1,
+        Expression|Select|string|int|float|bool|null $argument2
+    ): self {
+
+        if (is_string($argument1)) {
+            $key = $argument1;
+
+            if ($key === '') {
+                throw new RuntimeException("Expression can't be empty.");
+            }
+        } else {
+            $key = $argument1->getValue();
+        }
+
+        if (str_ends_with($key, ':')) {
+            throw new RuntimeException("Expression should not end with `:`.");
+        }
+
+        $key .= $operator;
+
+        if ($argument2 instanceof Expression) {
+            $key .= ':';
+
+            $value = $argument2->getValue();
+        } else {
+            $value = $argument2;
+        }
+
+        return new self($key, $value);
+    }
+
+    /**
+     * @param scalar[] $valueList
+     */
+    private static function createInOrNotInArray(
+        string $operator,
+        Expression|string $argument1,
+        array $valueList
+    ): self {
+
+        foreach ($valueList as $item) {
+            if (!is_scalar($item)) {
+                throw new RuntimeException("Array items must be scalar.");
+            }
+        }
+
+        if (is_string($argument1)) {
+            $key = $argument1;
+
+            if ($key === '') {
+                throw new RuntimeException("Expression can't be empty.");
+            }
+
+            if (str_ends_with($key, ':')) {
+                throw new RuntimeException("Expression can't end with `:`.");
+            }
+        } else {
+            $key = $argument1->getValue();
+        }
+
+        $key .= $operator;
+
+        return new self($key, $valueList);
+    }
+
+    private static function createInOrNotInSubQuery(
+        string $operator,
+        Expression|string $argument1,
+        Select $query
+    ): self {
+
+        if (is_string($argument1)) {
+            $key = $argument1;
+
+            if ($key === '') {
+                throw new RuntimeException("Expression can't be empty.");
+            }
+
+            if (str_ends_with($key, ':')) {
+                throw new RuntimeException("Expression can't end with `:`.");
+            }
+        } else {
+            $key = $argument1->getValue();
+        }
+
+        $key .= $operator;
+
+        return new self($key, $query);
+    }
+}

application/Espo/ORM/Query/Part/Where/Exists.php

@@ -0,0 +1,61 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part\Where;
+
+use Espo\ORM\Query\Part\WhereItem;
+use Espo\ORM\Query\Select;
+
+/**
+ * An EXISTS-operator. Immutable.
+ */
+class Exists implements WhereItem
+{
+    private function __construct(private Select $rawValue) {}
+
+    public function getRaw(): array
+    {
+        return ['EXISTS' => $this->getRawValue()];
+    }
+
+    public function getRawKey(): string
+    {
+        return 'EXISTS';
+    }
+
+    public function getRawValue(): Select
+    {
+        return $this->rawValue;
+    }
+
+    public static function create(Select $subQuery): self
+    {
+        return new self($subQuery);
+    }
+}

application/Espo/ORM/Query/Part/Where/Not.php

@@ -0,0 +1,80 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part\Where;
+
+use Espo\ORM\Query\Part\WhereItem;
+
+/**
+ * A NOT-operator. Immutable.
+ */
+class Not implements WhereItem
+{
+    /** @var array<string|int, mixed> */
+    private $rawValue = [];
+
+    public function getRaw(): array
+    {
+        return ['NOT' => $this->getRawValue()];
+    }
+
+    public function getRawKey(): string
+    {
+        return 'NOT';
+    }
+
+    /**
+     * @return array<string|int, mixed>
+     */
+    public function getRawValue(): array
+    {
+        return $this->rawValue;
+    }
+
+    /**
+     * @param array<string|int, mixed> $whereClause
+     */
+    public static function fromRaw(array $whereClause): self
+    {
+        if (count($whereClause) === 1 && array_keys($whereClause)[0] === 0) {
+            $whereClause = $whereClause[0];
+        }
+
+        $obj = new self();
+
+        $obj->rawValue = $whereClause;
+
+        return $obj;
+    }
+
+    public static function create(WhereItem $item): self
+    {
+        return self::fromRaw($item->getRaw());
+    }
+}

application/Espo/ORM/Query/Part/Where/OrGroup.php

@@ -0,0 +1,100 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part\Where;
+
+use Espo\ORM\Query\Part\WhereItem;
+
+/**
+ * OR-group. Immutable.
+ */
+class OrGroup implements WhereItem
+{
+
+    /** @var array<string|int, mixed> */
+    private $rawValue = [];
+
+    public function __construct()
+    {
+    }
+
+    public function getRaw(): array
+    {
+        return ['OR' => $this->rawValue];
+    }
+
+    public function getRawKey(): string
+    {
+        return 'OR';
+    }
+
+    /**
+     * @return array<string|int, mixed>
+     */
+    public function getRawValue(): array
+    {
+        return $this->rawValue;
+    }
+
+    /**
+     * Get a number of items.
+     */
+    public function getItemCount(): int
+    {
+        return count($this->rawValue);
+    }
+
+    /**
+     * @param array<string|int, mixed> $whereClause
+     */
+    public static function fromRaw(array $whereClause): self
+    {
+        $obj = new self();
+
+        $obj->rawValue = $whereClause;
+
+        return $obj;
+    }
+
+    public static function create(WhereItem ...$itemList): self
+    {
+        $builder = self::createBuilder();
+
+        foreach ($itemList as $item) {
+            $builder->add($item);
+        }
+
+        return $builder->build();
+    }
+
+    public static function createBuilder(): OrGroupBuilder
+    {
+        return new OrGroupBuilder();
+    }
+}

application/Espo/ORM/Query/Part/Where/OrGroupBuilder.php

@@ -0,0 +1,95 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part\Where;
+
+use Espo\ORM\Query\Part\WhereItem;
+
+class OrGroupBuilder
+{
+    /** @var array<string|int, mixed> */
+    private array $raw = [];
+
+    public function build(): OrGroup
+    {
+        return OrGroup::fromRaw($this->raw);
+    }
+
+    public function add(WhereItem $item): self
+    {
+        $key = $item->getRawKey();
+        $value = $item->getRawValue();
+
+        if ($item instanceof AndGroup) {
+            $this->raw = self::normalizeRaw($this->raw);
+
+            $this->raw[] = $value;
+
+            return $this;
+        }
+
+        if (count($this->raw) === 0) {
+            $this->raw[$key] = $value;
+
+            return $this;
+        }
+
+        $this->raw = self::normalizeRaw($this->raw);
+
+        $this->raw[] = [$key => $value];
+
+        return $this;
+    }
+
+    /**
+     * Merge with another OrGroup.
+     */
+    public function merge(OrGroup $orGroup): self
+    {
+        $this->raw = array_merge(
+            self::normalizeRaw($this->raw),
+            self::normalizeRaw($orGroup->getRawValue())
+        );
+
+        return $this;
+    }
+
+    /**
+     * @param array<string|int, mixed> $raw
+     * @return array<string|int, mixed>
+     */
+    private static function normalizeRaw(array $raw): array
+    {
+        if (count($raw) === 1 && array_keys($raw)[0] !== 0) {
+            return [$raw];
+        }
+
+        return $raw;
+    }
+}

application/Espo/ORM/Query/Part/WhereClause.php

@@ -0,0 +1,45 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part;
+
+use Espo\ORM\Query\Part\Where\AndGroup;
+
+/**
+ * A where-clause. Immutable.
+ *
+ * Immutable.
+ */
+class WhereClause extends AndGroup
+{
+    public function getRaw(): array
+    {
+        return $this->getRawValue();
+    }
+}

application/Espo/ORM/Query/Part/WhereItem.php

@@ -0,0 +1,45 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query\Part;
+
+/**
+ * Can be used as a where-clause.
+ */
+interface WhereItem
+{
+    /**
+     * @return array<string|int, mixed>
+     */
+    public function getRaw(): array;
+
+    public function getRawKey(): string;
+
+    public function getRawValue(): mixed;
+}

application/Espo/ORM/Query/Query.php

@@ -0,0 +1,43 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+/**
+ * Query parameters. Instances are immutable. Need to clone with a builder to get a copy for a further modification.
+ */
+interface Query
+{
+    /**
+     * Get parameters in RAW format.
+     *
+     * @return array<string, mixed>
+     */
+    public function getRaw(): array;
+}

application/Espo/ORM/Query/Select.php

@@ -0,0 +1,207 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use Espo\ORM\Query\Part\WhereClause;
+use Espo\ORM\Query\Part\Selection;
+use Espo\ORM\Query\Part\Order;
+use Espo\ORM\Query\Part\Expression;
+
+use RuntimeException;
+
+/**
+ * Select parameters.
+ *
+ * Immutable.
+ *
+ * @todo Add validation and normalization.
+ */
+class Select implements SelectingQuery
+{
+    use SelectingTrait;
+    use BaseTrait;
+
+    public const ORDER_ASC = Order::ASC;
+    public const ORDER_DESC = Order::DESC;
+
+    /**
+     * Get an entity type.
+     */
+    public function getFrom(): ?string
+    {
+        return $this->params['from'] ?? null;
+    }
+
+    /**
+     * Get a from-alias
+     */
+    public function getFromAlias(): ?string
+    {
+        return $this->params['fromAlias'] ?? null;
+    }
+
+    /**
+     * Get a from-query.
+     */
+    public function getFromQuery(): ?SelectingQuery
+    {
+        return $this->params['fromQuery'] ?? null;
+    }
+
+    /**
+     * Get an OFFSET.
+     */
+    public function getOffset(): ?int
+    {
+        return $this->params['offset'] ?? null;
+    }
+
+    /**
+     * Get a LIMIT.
+     */
+    public function getLimit(): ?int
+    {
+        return $this->params['limit'] ?? null;
+    }
+
+    /**
+     * Get USE INDEX (list of indexes).
+     *
+     * @return string[]
+     */
+    public function getUseIndex(): array
+    {
+        return $this->params['useIndex'] ?? [];
+    }
+
+    /**
+     * Get SELECT items.
+     *
+     * @return Selection[]
+     */
+    public function getSelect(): array
+    {
+        return array_map(
+            function ($item) {
+                if (is_array($item) && count($item)) {
+                    return Selection::fromString($item[0])
+                        ->withAlias($item[1] ?? null);
+                }
+
+                if (is_string($item)) {
+                    return Selection::fromString($item);
+                }
+
+                throw new RuntimeException("Bad select item.");
+            },
+            $this->params['select'] ?? []
+        );
+    }
+
+    /**
+     * Whether DISTINCT is applied.
+     */
+    public function isDistinct(): bool
+    {
+        return $this->params['distinct'] ?? false;
+    }
+
+    /**
+     * Whether a FOR SHARE lock mode is set.
+     */
+    public function isForShare(): bool
+    {
+        return $this->params['forShare'] ?? false;
+    }
+
+    /**
+     * Whether a FOR UPDATE lock mode is set.
+     */
+    public function isForUpdate(): bool
+    {
+        return $this->params['forUpdate'] ?? false;
+    }
+
+    /**
+     * Get GROUP BY items.
+     *
+     * @return Expression[]
+     */
+    public function getGroup(): array
+    {
+        return array_map(
+            function (string $item) {
+                return Expression::create($item);
+            },
+            $this->params['groupBy'] ?? []
+        );
+    }
+
+    /**
+     * Get HAVING clause.
+     */
+    public function getHaving(): ?WhereClause
+    {
+        $havingClause = $this->params['havingClause'] ?? null;
+
+        if ($havingClause === null || $havingClause === []) {
+            return null;
+        }
+
+        $having = WhereClause::fromRaw($havingClause);
+
+        if (!$having instanceof WhereClause) {
+            throw new RuntimeException();
+        }
+
+        return $having;
+    }
+
+    /**
+     * @param array<string, mixed> $params
+     */
+    private function validateRawParams(array $params): void
+    {
+        $this->validateRawParamsSelecting($params);
+
+        if (
+            (
+                !empty($params['joins']) ||
+                !empty($params['leftJoins']) ||
+                !empty($params['whereClause']) ||
+                !empty($params['orderBy'])
+            )
+            &&
+            empty($params['from']) && empty($params['fromQuery'])
+        ) {
+            throw new RuntimeException("Select params: Missing 'from'.");
+        }
+    }
+}

application/Espo/ORM/Query/SelectBuilder.php

@@ -0,0 +1,335 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use Espo\ORM\Query\Part\Expression;
+use Espo\ORM\Query\Part\Selection;
+use Espo\ORM\Query\Part\WhereItem;
+
+use InvalidArgumentException;
+use RuntimeException;
+
+class SelectBuilder implements Builder
+{
+    use SelectingBuilderTrait;
+
+    /**
+     * Create an instance.
+     */
+    public static function create(): self
+    {
+        return new self();
+    }
+
+    /**
+     * Build a SELECT query.
+     */
+    public function build(): Select
+    {
+        return Select::fromRaw($this->params);
+    }
+
+    /**
+     * Clone an existing query for a subsequent modifying and building.
+     */
+    public function clone(Select $query): self
+    {
+        $this->cloneInternal($query);
+
+        return $this;
+    }
+
+    /**
+     * Set FROM. For what entity type to build a query.
+     */
+    public function from(string $entityType, ?string $alias = null): self
+    {
+        if (isset($this->params['from']) && $entityType !== $this->params['from']) {
+            throw new RuntimeException("Method 'from' can be called only once.");
+        }
+
+        if (isset($this->params['fromQuery'])) {
+            throw new RuntimeException("Method 'from' can't be if 'fromQuery' is set.");
+        }
+
+        $this->params['from'] = $entityType;
+
+        if ($alias) {
+            $this->params['fromAlias'] = $alias;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Set FROM sub-query.
+     */
+    public function fromQuery(SelectingQuery $query, string $alias): self
+    {
+        if (isset($this->params['from'])) {
+            throw new RuntimeException("Method 'fromQuery' can be called only once.");
+        }
+
+        if (isset($this->params['fromQuery'])) {
+            throw new RuntimeException("Method 'fromQuery' can't be if 'from' is set.");
+        }
+
+        if ($alias === '') {
+            throw new RuntimeException("Alias can't be empty.");
+        }
+
+        $this->params['fromQuery'] = $query;
+        $this->params['fromAlias'] = $alias;
+
+        return $this;
+    }
+
+    /**
+     * Set DISTINCT parameter.
+     */
+    public function distinct(): self
+    {
+        $this->params['distinct'] = true;
+
+        return $this;
+    }
+
+    /**
+     * Apply OFFSET and LIMIT.
+     */
+    public function limit(?int $offset = null, ?int $limit = null): self
+    {
+        $this->params['offset'] = $offset;
+        $this->params['limit'] = $limit;
+
+        return $this;
+    }
+
+    /**
+     * Specify SELECT. Columns and expressions to be selected. If not called, then
+     * all entity attributes will be selected. Passing an array will reset
+     * previously set items. Passing a SelectExpression|Expression|string will append the item.
+     *
+     * Usage options:
+     * * `select(SelectExpression $expression)`
+     * * `select([$expr1, $expr2, ...])`
+     * * `select(string $expression, string $alias)`
+     *
+     * @param Selection|Selection[]|Expression|Expression[]|string[]|string|array<int, string[]|string> $select
+     * An array of expressions or one expression.
+     * @param string|null $alias An alias. Actual if the first parameter is not an array.
+     */
+    public function select($select, ?string $alias = null): self
+    {
+        /** @phpstan-var mixed $select */
+
+        if (is_array($select)) {
+            $this->params['select'] = $this->normalizeSelectExpressionArray($select);
+
+            return $this;
+        }
+
+        if ($select instanceof Expression) {
+            $select = $select->getValue();
+        } else if ($select instanceof Selection) {
+            $alias = $alias ?? $select->getAlias();
+            $select = $select->getExpression()->getValue();
+        }
+
+        if (is_string($select)) {
+            $this->params['select'] = $this->params['select'] ?? [];
+
+            $this->params['select'][] = $alias ?
+                [$select, $alias] :
+                $select;
+
+            return $this;
+        }
+
+        throw new InvalidArgumentException();
+    }
+
+    /**
+     * Specify GROUP BY.
+     * Passing an array will reset previously set items.
+     * Passing a string|Expression will append an item.
+     *
+     * Usage options:
+     * * `groupBy(Expression|string $expression)`
+     * * `groupBy([$expr1, $expr2, ...])`
+     *
+     * @param Expression|Expression[]|string|string[] $groupBy
+     */
+    public function group($groupBy): self
+    {
+        /** @phpstan-var mixed $groupBy */
+
+        if (is_array($groupBy)) {
+            $this->params['groupBy'] = $this->normalizeExpressionItemArray($groupBy);
+
+            return $this;
+        }
+
+        if ($groupBy instanceof Expression) {
+            $groupBy = $groupBy->getValue();
+        }
+
+        if (is_string($groupBy)) {
+            $this->params['groupBy'] = $this->params['groupBy'] ?? [];
+
+            $this->params['groupBy'][] = $groupBy;
+
+            return $this;
+        }
+
+        throw new InvalidArgumentException();
+    }
+
+    /**
+     * @deprecated Use `group` method.
+     * @param Expression|Expression[]|string|string[] $groupBy
+     */
+    public function groupBy($groupBy): self
+    {
+        return $this->group($groupBy);
+    }
+
+    /**
+     * Use index.
+     */
+    public function useIndex(string $index): self
+    {
+        $this->params['useIndex'] = $this->params['useIndex'] ?? [];
+
+        $this->params['useIndex'][] = $index;
+
+        return $this;
+    }
+
+    /**
+     * Add a HAVING clause.
+     *
+     * Usage options:
+     * * `having(WhereItem $clause)`
+     * * `having(array $clause)`
+     * * `having(string $key, string $value)`
+     *
+     * @param WhereItem|array<int|string, mixed>|string $clause A key or where clause.
+     * @param mixed[]|scalar|null $value A value. Omitted if the first argument is not string.
+     */
+    public function having($clause, $value = null): self
+    {
+        $this->applyWhereClause('havingClause', $clause, $value);
+
+        return $this;
+    }
+
+    /**
+     * Lock selected rows in shared mode. To be used within a transaction.
+     */
+    public function forShare(): self
+    {
+        if (isset($this->params['forUpdate'])) {
+            throw new RuntimeException("Can't use two lock modes together.");
+        }
+
+        $this->params['forShare'] = true;
+
+        return $this;
+    }
+
+    /**
+     * Lock selected rows. To be used within a transaction.
+     */
+    public function forUpdate(): self
+    {
+        if (isset($this->params['forShare'])) {
+            throw new RuntimeException("Can't use two lock modes together.");
+        }
+
+        $this->params['forUpdate'] = true;
+
+        return $this;
+    }
+
+    /**
+     * @todo Remove?
+     */
+    public function withDeleted(): self
+    {
+        $this->params['withDeleted'] = true;
+
+        return $this;
+    }
+
+    /**
+     * @param array<Expression|Selection|mixed[]> $itemList
+     * @return array<array{0: string, 1?: string}|string>
+     */
+    private function normalizeSelectExpressionArray(array $itemList): array
+    {
+        $resultList = [];
+
+        foreach ($itemList as $item) {
+            if ($item instanceof Expression) {
+                $resultList[] = $item->getValue();
+
+                continue;
+            }
+
+            if ($item instanceof Selection) {
+                $resultList[] = $item->getAlias() ?
+                    [$item->getExpression()->getValue(), $item->getAlias()] :
+                    [$item->getExpression()->getValue()];
+
+                continue;
+            }
+
+            if (!is_array($item) || !count($item) || !$item[0] instanceof Expression) {
+                /** @var array{0:string,1?:string} $item */
+                $resultList[] = $item;
+
+                continue;
+            }
+
+            $newItem = [$item[0]->getValue()];
+
+            if (count($item) > 1) {
+                $newItem[] = $item[1];
+            }
+
+            /** @var array{0: string, 1?: string} $newItem */
+
+            $resultList[] = $newItem;
+        }
+
+        return $resultList;
+    }
+}

application/Espo/ORM/Query/SelectingBuilderTrait.php

@@ -0,0 +1,429 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use Espo\ORM\Query\Part\WhereItem;
+use Espo\ORM\Query\Part\Expression;
+use Espo\ORM\Query\Part\Order;
+use Espo\ORM\Query\Part\Join;
+
+use InvalidArgumentException;
+use LogicException;
+use RuntimeException;
+
+trait SelectingBuilderTrait
+{
+    use BaseBuilderTrait;
+
+    /**
+     * Add a WHERE clause.
+     *
+     * Usage options:
+     * * `where(WhereItem $clause)`
+     * * `where(array $clause)`
+     * * `where(string $key, string $value)`
+     *
+     * @param WhereItem|array<string|int, mixed>|string $clause A key or where clause.
+     * @param mixed[]|scalar|null $value A value. Omitted if the first argument is not string.
+     */
+    public function where($clause, $value = null): self
+    {
+        $this->applyWhereClause('whereClause', $clause, $value);
+
+        return $this;
+    }
+
+    /**
+     * @param WhereItem|array<string|int, mixed>|string $clause A key or where clause.
+     * @param mixed[]|scalar|null $value A value. Omitted if the first argument is not string.
+     */
+    private function applyWhereClause(string $type, $clause, $value): void
+    {
+        if ($clause instanceof WhereItem) {
+            $clause = $clause->getRaw();
+        }
+
+        $this->params[$type] = $this->params[$type] ?? [];
+
+        $original = $this->params[$type];
+
+        if (!is_string($clause) && !is_array($clause)) {
+            throw new InvalidArgumentException("Bad where clause.");
+        }
+
+        if (is_array($clause)) {
+            $new = $clause;
+        }
+
+        if (is_string($clause)) {
+            $new = [$clause => $value];
+        }
+
+        $containsSameKeys = (bool) count(
+            array_intersect(
+                array_keys($new),
+                array_keys($original)
+            )
+        );
+
+        if ($containsSameKeys) {
+            $this->params[$type][] = $new;
+
+            return;
+        }
+
+        $this->params[$type] = $new + $original;
+    }
+
+    /**
+     * Apply ORDER. Passing an array will override previously set items.
+     * Passing non-array will append an item,
+     *
+     * Usage options:
+     * * `order(OrderExpression $expression)
+     * * `order([$expr1, $expr2, ...])
+     * * `order(string $expression, string $direction)
+     *
+     * @param Order|Order[]|Expression|string|array<int, string[]>|string[] $orderBy
+     * An attribute to order by or an array or order items.
+     * Passing an array will reset a previously set order.
+     * @param (Order::ASC|Order::DESC)|bool|null $direction A direction. True for DESC.
+     */
+    public function order($orderBy, $direction = null): self
+    {
+        if (is_bool($direction)) {
+            $direction = $direction ? Order::DESC : Order::ASC;
+        }
+
+        if (is_array($orderBy)) {
+            $this->params['orderBy'] = $this->normalizeOrderExpressionItemArray(
+                $orderBy,
+                $direction ?? Order::ASC
+            );
+
+            return $this;
+        }
+
+        if (!$orderBy) {
+            throw new InvalidArgumentException();
+        }
+
+        $this->params['orderBy'] = $this->params['orderBy'] ?? [];
+
+        if ($orderBy instanceof Expression) {
+            $orderBy = $orderBy->getValue();
+            $direction = $direction ?? Order::ASC;
+        } else if ($orderBy instanceof Order) {
+            $direction = $direction ?? $orderBy->getDirection();
+            $orderBy = $orderBy->getExpression()->getValue();
+        } else {
+            $direction = $direction ?? Order::ASC;
+        }
+
+        $this->params['orderBy'][] = [$orderBy, $direction];
+
+        return $this;
+    }
+
+    /**
+     * Add JOIN.
+     *
+     * @param Join|string|Select $target A relation name, table or sub-query. A relation name should be in camelCase,
+     *     a table in CamelCase.
+     * @param ?string $alias An alias.
+     * @param WhereItem|array<string|int, mixed>|null $conditions Join conditions.
+     */
+    public function join(
+        $target,
+        ?string $alias = null,
+        WhereItem|array|null $conditions = null
+    ): self {
+
+        return $this->joinInternal('joins', $target, $alias, $conditions);
+    }
+
+    /**
+     * Add LEFT JOIN.
+     *
+     * @param Join|string|Select $target A relation name, table or sub-query. A relation name should be in camelCase,
+     *     a table in CamelCase.
+     * @param ?string $alias An alias.
+     * @param WhereItem|array<string|int, mixed>|null $conditions Join conditions.
+     */
+    public function leftJoin(
+        $target,
+        ?string $alias = null,
+        WhereItem|array|null $conditions = null
+    ): self {
+
+        return $this->joinInternal('leftJoins', $target, $alias, $conditions);
+    }
+
+    /**
+     * @param 'leftJoins'|'joins' $type
+     * @todo Support USE INDEX in Join.
+     * @param Join|string|Select $target $target
+     * @param WhereItem|array<string|int, mixed>|null $conditions
+     */
+    private function joinInternal(
+        string $type,
+        $target,
+        ?string $alias = null,
+        WhereItem|array|null $conditions = null
+    ): self {
+
+        $onlyMiddle = false;
+        $isLateral = false;
+
+        /** @var string|Join|array<int, mixed> $target */
+
+        $joinType = null;
+
+        if ($target instanceof Join) {
+            $alias = $alias ?? $target->getAlias();
+            $conditions = $conditions ?? $target->getConditions();
+            $onlyMiddle = $target->isOnlyMiddle();
+            $isLateral = $target->isLateral();
+            $joinType = $target->getType();
+
+            $target = $target->getTarget();
+        }
+
+        if ($type === 'leftJoins') {
+            $joinType = Join\JoinType::left;
+        }
+
+        if ($target instanceof Select && !$alias) {
+            throw new LogicException("Sub-query join can't be used w/o alias.");
+        }
+
+        $noLeftAlias = false;
+
+        if ($conditions instanceof WhereItem) {
+            $conditions = $conditions->getRaw();
+
+            $noLeftAlias = true;
+        }
+
+        $this->params['joins'] ??= [];
+
+        // For bc.
+        // @todo Remove in v10.0.
+        if (is_array($target)) {
+            // @todo Log deprecation.
+
+            $joinList = $target;
+
+            $this->params[$type] ??= [];
+
+            foreach ($joinList as $item) {
+                $this->params[$type][] = $item;
+            }
+
+            return $this;
+        }
+
+        if (
+            is_null($alias) &&
+            is_null($conditions) &&
+            is_string($target) &&
+            $this->hasJoinAliasInternal('joins', $target)
+        ) {
+            return $this;
+        }
+
+        $params = [];
+
+        if ($noLeftAlias) {
+            $params['noLeftAlias'] = true;
+        }
+
+        if ($onlyMiddle) {
+            $params['onlyMiddle'] = true;
+        }
+
+        if ($isLateral) {
+            $params['isLateral'] = true;
+        }
+
+        $params['type'] = $joinType;
+
+        $this->params['joins'][] = [$target, $alias, $conditions, $params];
+
+        return $this;
+    }
+
+    private function hasJoinAliasInternal(string $type, string $alias): bool
+    {
+        $joins = $this->params[$type] ?? [];
+
+        if (in_array($alias, $joins)) {
+            return true;
+        }
+
+        foreach ($joins as $item) {
+            if (is_array($item) && count($item) > 1) {
+                if ($item[1] === $alias) {
+                    return true;
+                }
+
+                if (
+                    $item[1] === null &&
+                    $item[0] === $alias &&
+                    lcfirst($item[0]) === $alias
+                ) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * @deprecated As of v9.2.0. Use `hasJoinAlias`.
+     */
+    public function hasLeftJoinAlias(string $alias): bool
+    {
+        return $this->hasJoinAlias($alias);
+    }
+
+    /**
+     * Whether an alias is in joins.
+     */
+    public function hasJoinAlias(string $alias): bool
+    {
+        return $this->hasJoinAliasInternal('joins', $alias) ||
+            // For bc.
+            $this->hasJoinAliasInternal('leftJoins', $alias);
+    }
+
+    /**
+     * @param array<Expression|mixed[]> $itemList
+     * @return array<array{0: string, 1?: string}|string>
+     */
+    private function normalizeExpressionItemArray(array $itemList): array
+    {
+        $resultList = [];
+
+        foreach ($itemList as $item) {
+            if ($item instanceof Expression) {
+                $resultList[] = $item->getValue();
+
+                continue;
+            }
+
+            if (!is_array($item) || !count($item) || !$item[0] instanceof Expression) {
+                /** @var array{0:string, 1?:string} $item */
+                $resultList[] = $item;
+
+                continue;
+            }
+
+            $newItem = [$item[0]->getValue()];
+
+            if (count($item) > 1) {
+                $newItem[] = $item[1];
+            }
+
+            /** @var array{0:string,1?:string} $newItem */
+
+            $resultList[] = $newItem;
+        }
+
+        return $resultList;
+    }
+
+    /**
+     * @param array<Order|mixed[]|string> $itemList
+     * @param string|bool|null $direction
+     * @return array<array{string, string|bool}>
+     */
+    private function normalizeOrderExpressionItemArray(array $itemList, $direction): array
+    {
+        $resultList = [];
+
+        foreach ($itemList as $item) {
+            if (is_string($item)) {
+                $resultList[] = [$item, $direction];
+
+                continue;
+            }
+
+            if (is_int($item)) {
+                $resultList[] = [(string) $item, $direction];
+
+                continue;
+            }
+
+            if ($item instanceof Order) {
+                $resultList[] = [
+                    $item->getExpression()->getValue(),
+                    $item->getDirection()
+                ];
+
+                continue;
+            }
+
+            if ($item instanceof Expression) {
+                $resultList[] = [
+                    $item->getValue(),
+                    $direction
+                ];
+
+                continue;
+            }
+
+            if (!is_array($item) || !count($item)) {
+                throw new RuntimeException("Bad order item.");
+            }
+
+            $itemValue = $item[0] instanceof Expression ?
+                $item[0]->getValue() :
+                $item[0];
+
+            if (!is_string($itemValue) && !is_int($itemValue)) {
+                throw new RuntimeException("Bad order item.");
+            }
+
+            $itemDirection = count($item) > 1 ? $item[1] : $direction;
+
+            if (is_bool($itemDirection)) {
+                $itemDirection = $itemDirection ?
+                    Order::DESC :
+                    Order::ASC;
+            }
+
+            $resultList[] = [$itemValue, $itemDirection];
+        }
+
+        return $resultList;
+    }
+}

application/Espo/ORM/Query/SelectingQuery.php

@@ -0,0 +1,33 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+interface SelectingQuery extends Query
+{}

application/Espo/ORM/Query/SelectingTrait.php

@@ -0,0 +1,146 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use Espo\ORM\Query\Part\Order;
+use Espo\ORM\Query\Part\WhereClause;
+use Espo\ORM\Query\Part\Join;
+
+use RuntimeException;
+
+trait SelectingTrait
+{
+    /**
+     * Get ORDER items.
+     *
+     * @return Order[]
+     */
+    public function getOrder(): array
+    {
+        return array_map(
+            function ($item) {
+                if (is_array($item) && count($item)) {
+                    $itemValue = is_int($item[0]) ? (string) $item[0] : $item[0];
+
+                    return Order::fromString($itemValue)
+                        ->withDirection($item[1] ?? Order::ASC);
+                }
+
+                if (is_string($item)) {
+                    return Order::fromString($item);
+                }
+
+                throw new RuntimeException("Bad order item.");
+            },
+            $this->params['orderBy'] ?? []
+        );
+    }
+
+    /**
+     * Get WHERE clause.
+     */
+    public function getWhere(): ?WhereClause
+    {
+        $whereClause = $this->params['whereClause'] ?? null;
+
+        if ($whereClause === null || $whereClause === []) {
+            return null;
+        }
+
+        $where = WhereClause::fromRaw($whereClause);
+
+        if (!$where instanceof WhereClause) {
+            throw new RuntimeException();
+        }
+
+        return $where;
+    }
+
+    /**
+     * Get JOIN items.
+     *
+     * @return Join[]
+     */
+    public function getJoins(): array
+    {
+        return array_map(
+            function ($item) {
+                if (is_string($item)) {
+                    $item = [$item];
+                }
+
+                $conditions = isset($item[2]) ?
+                    WhereClause::fromRaw($item[2]) : null;
+
+                $params = $item[3] ?? [];
+
+                $type = $params['type'] ?? null;
+                $type ??= Join\JoinType::inner;
+
+                return Join::create($item[0])
+                    ->withAlias($item[1] ?? null)
+                    ->withConditions($conditions)
+                    ->withType($type);
+            },
+            $this->params['joins'] ?? []
+        );
+    }
+
+    /**
+     * @return Join[]
+     * @deprecated As of 9.2.0. Use getJoins and check join type.
+     */
+    public function getLeftJoins(): array
+    {
+        return array_map(
+            function ($item) {
+                if (is_string($item)) {
+                    $item = [$item];
+                }
+
+                $conditions = isset($item[2]) ?
+                    WhereClause::fromRaw($item[2]) : null;
+
+                return Join::create($item[0])
+                    ->withAlias($item[1] ?? null)
+                    ->withConditions($conditions)
+                    ->withLeft();
+            },
+            $this->params['leftJoins'] ?? []
+        );
+    }
+
+    /**
+     * @param array<string, mixed> $params
+     */
+    private static function validateRawParamsSelecting(array $params): void
+    {
+    }
+}

application/Espo/ORM/Query/Union.php

@@ -0,0 +1,52 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use RuntimeException;
+
+/**
+ * Union parameters.
+ *
+ * Immutable.
+ */
+class Union implements SelectingQuery
+{
+    use BaseTrait;
+
+    /**
+     * @param array<string, mixed> $params
+     */
+    private function validateRawParams(array $params): void
+    {
+        if (empty($params['queries'])) {
+            throw new RuntimeException("Union params: No query were added.");
+        }
+    }
+}

application/Espo/ORM/Query/UnionBuilder.php

@@ -0,0 +1,146 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use Espo\ORM\Query\Part\Order;
+
+use InvalidArgumentException;
+
+class UnionBuilder implements Builder
+{
+    use BaseBuilderTrait;
+
+    /**
+     * Create an instance.
+     */
+    public static function create(): self
+    {
+        return new self();
+    }
+
+    /**
+     * Build a UNION select query.
+     */
+    public function build(): Union
+    {
+        return Union::fromRaw($this->params);
+    }
+
+    /**
+     * Clone an existing query for a subsequent modifying and building.
+     */
+    public function clone(Union $query): self
+    {
+        $this->cloneInternal($query);
+
+        return $this;
+    }
+
+    /**
+     * Use UNION ALL.
+     */
+    public function all(): self
+    {
+        $this->params['all'] = true;
+
+        return $this;
+    }
+
+    public function query(Select $query): self
+    {
+        $this->params['queries'] = $this->params['queries'] ?? [];
+        $this->params['queries'][] = $query;
+
+        return $this;
+    }
+
+    /**
+     * Apply OFFSET and LIMIT.
+     */
+    public function limit(?int $offset = null, ?int $limit = null): self
+    {
+        $this->params['offset'] = $offset;
+        $this->params['limit'] = $limit;
+
+        return $this;
+    }
+
+    /**
+     * Apply ORDER.
+     *
+     * @param string|array<array{string, (Order::ASC|Order::DESC)|bool}|array{string}> $orderBy A select alias.
+     * @param (Order::ASC|Order::DESC)|bool $direction A direction. True for DESC.
+     */
+    public function order($orderBy, string|bool $direction = Order::ASC): self
+    {
+        if (is_bool($direction)) {
+            $direction = $direction ? Order::DESC : Order::ASC;
+        }
+
+        if (!$orderBy) {
+            throw new InvalidArgumentException();
+        }
+
+        if (is_array($orderBy)) {
+            foreach ($orderBy as $item) {
+                /** @var mixed[] $item */
+
+                if (count($item) === 2) {
+                    /** @var array{string, bool|(Order::ASC|Order::DESC)} $item */
+                    $this->order($item[0], $item[1]);
+
+                    continue;
+                }
+
+                if (count($item) === 1) {
+                    /** @var array{string} $item */
+                    $this->order($item[0]);
+
+                    continue;
+                }
+
+                throw new InvalidArgumentException("Bad order.");
+            }
+
+            return $this;
+        }
+
+        /** @var object|scalar $orderBy */
+
+        if (!is_string($orderBy) && !is_int($orderBy)) {
+            throw new InvalidArgumentException("Bad order.");
+        }
+
+        $this->params['orderBy'] = $this->params['orderBy'] ?? [];
+        $this->params['orderBy'][] = [$orderBy, $direction];
+
+        return $this;
+    }
+}

application/Espo/ORM/Query/Update.php

@@ -0,0 +1,109 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use Espo\ORM\Query\Part\Expression;
+use RuntimeException;
+
+/**
+ * Update parameters.
+ *
+ * Immutable.
+ */
+class Update implements Query
+{
+    use SelectingTrait;
+    use BaseTrait;
+
+    /**
+     * Get an entity type.
+     */
+    public function getIn(): string
+    {
+        $in = $this->params['from'];
+
+        if ($in === null) {
+            throw new RuntimeException("Missing 'in'.");
+        }
+
+        return $in;
+    }
+
+    /**
+     * Get a LIMIT.
+     */
+    public function getLimit(): ?int
+    {
+        return $this->params['limit'] ?? null;
+    }
+
+    /**
+     * Get SET values.
+     *
+     * @return array<string, scalar|Expression|null>
+     */
+    public function getSet(): array
+    {
+        $set = [];
+        /** @var array<string, ?scalar> $raw */
+        $raw = $this->params['set'];
+
+        foreach ($raw as $key => $value) {
+            if (str_ends_with($key, ':')) {
+                $key = substr($key, 0, -1);
+                $value = Expression::create((string) $value);
+            }
+
+            $set[$key] = $value;
+        }
+
+        return $set;
+    }
+
+    /**
+     * @param array<string, mixed> $params
+     */
+    private function validateRawParams(array $params): void
+    {
+        $this->validateRawParamsSelecting($params);
+
+        $from = $params['from'] ?? null;
+
+        if (!$from || !is_string($from)) {
+            throw new RuntimeException("Update params: Missing 'in'.");
+        }
+
+        $set = $params['set'] ?? null;
+
+        if (!$set || !is_array($set)) {
+            throw new RuntimeException("Update params: Bad or missing 'set' parameter.");
+        }
+    }
+}

application/Espo/ORM/Query/UpdateBuilder.php

@@ -0,0 +1,114 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\ORM\Query;
+
+use Espo\ORM\Query\Part\Expression;
+use RuntimeException;
+
+class UpdateBuilder implements Builder
+{
+    use SelectingBuilderTrait;
+
+    /**
+     * Create an instance.
+     */
+    public static function create(): self
+    {
+        return new self();
+    }
+
+    /**
+     * Build a UPDATE query.
+     */
+    public function build(): Update
+    {
+        return Update::fromRaw($this->params);
+    }
+
+    /**
+     * Clone an existing query for a subsequent modifying and building.
+     */
+    public function clone(Update $query): self
+    {
+        $this->cloneInternal($query);
+
+        return $this;
+    }
+
+    /**
+     * For what entity type to build a query.
+     */
+    public function in(string $entityType): self
+    {
+        if (isset($this->params['from'])) {
+            throw new RuntimeException("Method 'in' can be called only once.");
+        }
+
+        $this->params['from'] = $entityType;
+
+        return $this;
+    }
+
+    /**
+     * Values to set. Column => Value map.
+     *
+     * @param array<string, scalar|Expression|null> $set
+     */
+    public function set(array $set): self
+    {
+        $modified = [];
+
+        foreach ($set as $key => $value) {
+            if (!$value instanceof Expression) {
+                $modified[$key] = $value;
+
+                continue;
+            }
+
+            $newKey = rtrim($key, ':')  . ':';
+
+            $modified[$newKey] = $value->getValue();
+        }
+
+        $this->params['set'] = $modified;
+
+        return $this;
+    }
+
+    /**
+     * Apply LIMIT.
+     */
+    public function limit(?int $limit = null): self
+    {
+        $this->params['limit'] = $limit;
+
+        return $this;
+    }
+}