Added a custom function to make PostgresSQL searches case insensitive

This is required only for postgres as every other database is case invariant by default. But to achieve a portable way, we implement it via a custom DQL function.

This fixes issue #784

src/Doctrine/Functions/ILike.php

@@ -0,0 +1,71 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2024 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  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/>.
+ */
+
+declare(strict_types=1);
+
+
+namespace App\Doctrine\Functions;
+
+use Doctrine\DBAL\Platforms\AbstractMySQLPlatform;
+use Doctrine\DBAL\Platforms\PostgreSQLPlatform;
+use Doctrine\DBAL\Platforms\SQLitePlatform;
+use Doctrine\ORM\Query\AST\Functions\FunctionNode;
+use Doctrine\ORM\Query\Parser;
+use Doctrine\ORM\Query\SqlWalker;
+use Doctrine\ORM\Query\TokenType;
+
+/**
+ * A platform invariant version of the case-insensitive LIKE operation.
+ * On MySQL and SQLite this is the normal LIKE, but on PostgreSQL it is the ILIKE operator.
+ */
+class ILike extends FunctionNode
+{
+
+    public $value = null;
+
+    public $expr = null;
+
+    public function parse(Parser $parser): void
+    {
+        $parser->match(TokenType::T_IDENTIFIER);
+        $parser->match(TokenType::T_OPEN_PARENTHESIS);
+        $this->value = $parser->StringPrimary();
+        $parser->match(TokenType::T_COMMA);
+        $this->expr = $parser->StringExpression();
+        $parser->match(TokenType::T_CLOSE_PARENTHESIS);
+    }
+
+    public function getSql(SqlWalker $sqlWalker): string
+    {
+        $platform = $sqlWalker->getConnection()->getDatabasePlatform();
+
+        //
+        if ($platform instanceof AbstractMySQLPlatform || $platform instanceof SQLitePlatform) {
+            $operator = 'LIKE';
+        } elseif ($platform instanceof PostgreSQLPlatform) {
+            //Use the case-insensitive operator, to have the same behavior as MySQL
+            $operator = 'ILIKE';
+        } else {
+            throw new \RuntimeException('Platform ' . gettype($platform) . ' does not support case insensitive like expressions.');
+        }
+
+        return '(' . $this->value->dispatch($sqlWalker) . ' ' . $operator . ' ' . $this->expr->dispatch($sqlWalker) . ')';
+    }
+}