fix(database): convert backtick identifiers to double quotes for PostgreSQL

Query::compile() stripped backtick quoting entirely for PostgreSQL,
leaving identifiers unquoted. This breaks for reserved words like
order, user, group, and type. Now converts backticks to double quotes,
which is the correct PostgreSQL identifier quoting.

Author: laylatichy

packages/database/src/Query.php

@@ -76,7 +76,7 @@ public function compile(): ImmutableString
         }
 
         if ($dialect === DatabaseDialect::POSTGRESQL) {
-            $sql = str_replace('`', '', $sql);
+            $sql = str_replace('`', '"', $sql);
         }
 
         return new ImmutableString($sql);

packages/database/tests/QueryCompileTest.php

@@ -0,0 +1,177 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Tempest\Database\Tests;
+
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+use Tempest\Container\GenericContainer;
+use Tempest\Database\Config\MysqlConfig;
+use Tempest\Database\Config\PostgresConfig;
+use Tempest\Database\Config\SQLiteConfig;
+use Tempest\Database\Connection\PDOConnection;
+use Tempest\Database\Database;
+use Tempest\Database\GenericDatabase;
+use Tempest\Database\Query;
+use Tempest\Database\Transactions\GenericTransactionManager;
+use Tempest\EventBus\EventBusConfig;
+use Tempest\EventBus\GenericEventBus;
+use Tempest\Mapper\SerializerFactory;
+
+final class QueryCompileTest extends TestCase
+{
+    protected function tearDown(): void
+    {
+        GenericContainer::setInstance(instance: null);
+
+        parent::tearDown();
+    }
+
+    private function createDatabaseWithMysqlDialect(): void
+    {
+        $config = new MysqlConfig();
+        $connection = new PDOConnection(config: $config);
+
+        $database = new GenericDatabase(
+            connection: $connection,
+            transactionManager: new GenericTransactionManager(connection: $connection),
+            serializerFactory: new SerializerFactory(container: new GenericContainer()),
+            eventBus: new GenericEventBus(
+                container: new GenericContainer(),
+                eventBusConfig: new EventBusConfig(),
+            ),
+        );
+
+        $container = new GenericContainer();
+        $container->singleton(
+            className: Database::class,
+            definition: $database
+        );
+        GenericContainer::setInstance(instance: $container);
+    }
+
+    private function createDatabaseWithPostgresDialect(): void
+    {
+        $config = new PostgresConfig();
+        $connection = new PDOConnection(config: $config);
+
+        $database = new GenericDatabase(
+            connection: $connection,
+            transactionManager: new GenericTransactionManager(connection: $connection),
+            serializerFactory: new SerializerFactory(container: new GenericContainer()),
+            eventBus: new GenericEventBus(
+                container: new GenericContainer(),
+                eventBusConfig: new EventBusConfig(),
+            ),
+        );
+
+        $container = new GenericContainer();
+        $container->singleton(
+            className: Database::class,
+            definition: $database
+        );
+        GenericContainer::setInstance(instance: $container);
+    }
+
+    private function createDatabaseWithSqliteDialect(): void
+    {
+        $config = new SQLiteConfig(path: ':memory:');
+        $connection = new PDOConnection(config: $config);
+
+        $database = new GenericDatabase(
+            connection: $connection,
+            transactionManager: new GenericTransactionManager(connection: $connection),
+            serializerFactory: new SerializerFactory(container: new GenericContainer()),
+            eventBus: new GenericEventBus(
+                container: new GenericContainer(),
+                eventBusConfig: new EventBusConfig(),
+            ),
+        );
+
+        $container = new GenericContainer();
+        $container->singleton(
+            className: Database::class,
+            definition: $database
+        );
+        GenericContainer::setInstance(instance: $container);
+    }
+
+    #[Test]
+    public function postgresql_converts_backticks_to_double_quotes(): void
+    {
+        $this->createDatabaseWithPostgresDialect();
+
+        $query = new Query(sql: 'SELECT `name`, `email` FROM `users` WHERE `id` = ?');
+
+        $this->assertSame(
+            'SELECT "name", "email" FROM "users" WHERE "id" = ?',
+            $query->compile()->toString(),
+        );
+    }
+
+    #[Test]
+    public function postgresql_handles_qualified_identifiers(): void
+    {
+        $this->createDatabaseWithPostgresDialect();
+
+        $query = new Query(sql: 'SELECT `users`.`name` FROM `users`');
+
+        $this->assertSame(
+            'SELECT "users"."name" FROM "users"',
+            $query->compile()->toString(),
+        );
+    }
+
+    #[Test]
+    public function postgresql_handles_reserved_words(): void
+    {
+        $this->createDatabaseWithPostgresDialect();
+
+        $query = new Query(sql: 'SELECT `order`, `user`, `type` FROM `group`');
+
+        $this->assertSame(
+            'SELECT "order", "user", "type" FROM "group"',
+            $query->compile()->toString(),
+        );
+    }
+
+    #[Test]
+    public function postgresql_passes_through_sql_without_backticks(): void
+    {
+        $this->createDatabaseWithPostgresDialect();
+
+        $query = new Query(sql: 'SELECT 1');
+
+        $this->assertSame(
+            'SELECT 1',
+            $query->compile()->toString()
+        );
+    }
+
+    #[Test]
+    public function mysql_retains_backticks(): void
+    {
+        $this->createDatabaseWithMysqlDialect();
+
+        $query = new Query(sql: 'SELECT `name` FROM `users` WHERE `id` = ?');
+
+        $this->assertSame(
+            'SELECT `name` FROM `users` WHERE `id` = ?',
+            $query->compile()->toString(),
+        );
+    }
+
+    #[Test]
+    public function sqlite_retains_backticks(): void
+    {
+        $this->createDatabaseWithSqliteDialect();
+
+        $query = new Query(sql: 'SELECT `name` FROM `users` WHERE `id` = ?');
+
+        $this->assertSame(
+            'SELECT `name` FROM `users` WHERE `id` = ?',
+            $query->compile()->toString(),
+        );
+    }
+}