[gjerokrsteski]

This is dedicated to foolowing posting: http://www.yiiframew...sql#add-comment "How to use nested DB transactions (MySQL 5+, PostgreSQL)"

I just have extended the method "public function rollBack()".

This check avoids the user from trying to rollback an transaction without a transaction-start.

  
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/**
   * @return bool|void
   * @throws PDOException
   */
  public function rollBack()
  {
    if ($this->transLevel == 0) {
      throw new PDOException(
        'trying to rollback without a transaction-start'
      );
    }

    $this->transLevel--;

    if ($this->transLevel == 0 || !$this->nestable()) {
      parent::rollBack();
    } else {
      $this->exec("ROLLBACK TO SAVEPOINT LEVEL{$this->transLevel}");
    }
  }

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