Merge::execute

public Merge::execute()

public function execute() {
  // Default options for merge queries.
  $this->queryOptions += array(
    'throw_exception' => TRUE,
  );

  try {
    if (!count($this->condition)) {
      throw new InvalidMergeQueryException(t('Invalid merge query: no conditions'));
    }
    $select = $this->connection->select($this->conditionTable)
      ->condition($this->condition);
    $select->addExpression('1');
    if (!$select->execute()->fetchField()) {
      try {
        $insert = $this->connection->insert($this->table)->fields($this->insertFields);
        if ($this->defaultFields) {
          $insert->useDefaults($this->defaultFields);
        }
        $insert->execute();
        return self::STATUS_INSERT;
      }
      catch (IntegrityConstraintViolationException $e) {
        // The insert query failed, maybe it's because a racing insert query
        // beat us in inserting the same row. Retry the select query, if it
        // returns a row, ignore the error and continue with the update
        // query below.
        if (!$select->execute()->fetchField()) {
          throw $e;
        }
      }
    }
    if ($this->needsUpdate) {
      $update = $this->connection->update($this->table)
        ->fields($this->updateFields)
        ->condition($this->condition);
      if ($this->expressionFields) {
        foreach ($this->expressionFields as $field => $data) {
          $update->expression($field, $data['expression'], $data['arguments']);
        }
      }
      $update->execute();
      return self::STATUS_UPDATE;
    }
  }
  catch (\Exception $e) {
    if ($this->queryOptions['throw_exception']) {
      throw $e;
    }
    else {
      return NULL;
    }
  }
}