Transactions

  1. Performing transactions
  2. Throwing exceptions

Performing transactions

Transactions are performed with the help of the transaction method.

use Opis\Database\Database;
use Opis\Database\Connection;

$connection = new Connection('mysql:host=localhost;dbname=test', 'username', 'password');
$db = new Database($connection);

$result = $db->transaction(function(Database $db){
    
    $db->insert(['user' => 'John Doe', 'email' => 'jd@foobar.com'])
       ->into('users');
       
    return $db->getConnection()->pdo()->lastInsertId();
});

You can pass a second argument to the transaction method, representing the value that will be returned when a transaction fails. The default value that is returned in case of a failure is null.

$result = $db->transaction(function(Database $db){
    // simulate failure
    throw new \Exception();
}, false);

var_dump($result); // bool(false)

Throwing exceptions

When doing a transaction, any exception that is thrown, gets caught and handled by the library itself. But there are some cases when such a behavior is not desirable. Changing the default behavior, and allowing exceptions to be thrown, is done by calling the throwTransactionExceptions method on the connection object.

$db->getConnection()->throwTransactionExceptions();

// No return value. Exception is thrown
$result = $db->transaction(function(Database $db){
    // simulate failure
    throw new \Exception();
}, false);

When you want to re-enable the default behavior, simply pass false as an argument to the method.

$db->getConnection()->throwTransactionExceptions(false);

// No exception is thrown, `false` is returned
$result = $db->transaction(function(Database $db){
    // simulate failure
    throw new \Exception();
}, false);