yii\db\mssql\PDO::rollBack PHP Method

Rollbacks a transaction. It is necessary to override PDO's method as MSSQL PDO driver does not natively support transactions.

public rollBack ( ) : boolean
return	boolean	the result of a transaction roll back.

    public function rollBack()
    {
        $this->exec('ROLLBACK TRANSACTION');
        return true;
    }

PDO