try { $pdo = new PDO('mysql:host=localhost;dbname=mydatabase', 'username', 'password'); $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); $pdo->beginTransaction(); //execute SQL queries here $pdo->commit(); } catch(PDOException $e) { $pdo->rollBack(); echo "Error: " . $e->getMessage(); }This code connects to a MySQL database, initiates a transaction, executes some SQL queries, and commits the transaction if all queries are successful. If an error occurs, the transaction is rolled back and an error message is displayed. Package library: The PDO class is built into PHP itself, so no external package library is required. However, you may need to install a database driver extension depending on the type of database you are connecting to. For example, to connect to a MySQL database, you would need the MySQL PDO driver extension.