Merge pull request #8649 from annando/annando/issue8550

Issue 8550: New experimental database configurations

src/Database/Database.php

@@ -135,8 +135,9 @@ class Database
 		}
 
 		$this->emulate_prepares = (bool)$this->configCache->get('database', 'emulate_prepares');
+		$this->pdo_emulate_prepares = (bool)$this->configCache->get('database', 'pdo_emulate_prepares');
 
-		if (class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
+		if (!$this->configCache->get('database', 'disable_pdo') && class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
 			$this->driver = 'pdo';
 			$connect      = "mysql:host=" . $server . ";dbname=" . $db;
 
@@ -150,7 +151,7 @@ class Database
 
 			try {
 				$this->connection = @new PDO($connect, $user, $pass);
-				$this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
+				$this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, $this->pdo_emulate_prepares);
 				$this->connected = true;
 			} catch (PDOException $e) {
 				$this->connected = false;
@@ -1046,7 +1047,7 @@ class Database
 		$success = $this->e("LOCK TABLES " . DBA::buildTableString($table) . " WRITE");
 
 		if ($this->driver == 'pdo') {
-			$this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
+			$this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, $this->pdo_emulate_prepares);
 		}
 
 		if (!$success) {
@@ -1079,7 +1080,7 @@ class Database
 		$success = $this->e("UNLOCK TABLES");
 
 		if ($this->driver == 'pdo') {
-			$this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
+			$this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, $this->pdo_emulate_prepares);
 			$this->e("SET autocommit=1");
 		} else {
 			$this->connection->autocommit(true);

static/defaults.config.php

@@ -45,8 +45,23 @@ return [
 		'database' => '',
 
 		// charset (String)
-		// Database connexion charset. Changing this value will likely corrupt special characters.
+		// Database connection charset. Changing this value will likely corrupt special characters.
 		'charset' => 'utf8mb4',
+
+		// emulate_prepares (Boolean) (Experimental)
+		// If enabled, prepared statements will be emulated.
+		// In combination with MySQLi this will cast all return values to strings.
+		'emulate_prepares' => false,
+
+		// pdo_emulate_prepares (Boolean) (Experimental)
+		// If enabled, the builtin emulation for prepared statements is used.
+		// Due to limitations of that emulation (all return values are casted as strings)
+		// this will most likely cause issues and should not be used on production systems.
+		'pdo_emulate_prepares' => false,
+
+		// disable_pdo (Boolean)
+		// PDO is used by default (if available). Otherwise MySQLi will be used.
+		'disable_pdo' => false,
 	],
 	'config' => [
 		// admin_email (Comma-separated list)

tests/Util/Database/StaticDatabase.php

@@ -56,6 +56,8 @@ class StaticDatabase extends Database
 		$this->driver = 'pdo';
 		$this->connection = self::$staticConnection;
 		$this->connected = true;
+		$this->emulate_prepares = false;
+		$this->pdo_emulate_prepares = false;
 
 		return $this->connected;
 	}