Upsert::execute

public Upsert::execute()

public function execute() {
  if (!$this->preExecute()) {
    return NULL;
  }

  // Default options for upsert queries.
  $this->queryOptions += array(
    'throw_exception' => TRUE,
  );

  // Default fields are always placed first for consistency.
  $insert_fields = array_merge($this->defaultFields, $this->insertFields);

  $table = $this->connection->escapeTable($this->table);

  // We have to execute multiple queries, therefore we wrap everything in a
  // transaction so that it is atomic where possible.
  $transaction = $this->connection->startTransaction();

  try {
    // First, lock the table we're upserting into.
    $this->connection->query('LOCK TABLE {' . $table . '} IN SHARE ROW EXCLUSIVE MODE', [], $this->queryOptions);

    // Second, delete all items first so we can do one insert.
    $unique_key_position = array_search($this->key, $insert_fields);
    $delete_ids = [];
    foreach ($this->insertValues as $insert_values) {
      $delete_ids[] = $insert_values[$unique_key_position];
    }

    // Delete in chunks when a large array is passed.
    foreach (array_chunk($delete_ids, 1000) as $delete_ids_chunk) {
      $this->connection->delete($this->table, $this->queryOptions)
        ->condition($this->key, $delete_ids_chunk, 'IN')
        ->execute();
    }

    // Third, insert all the values.
    $insert = $this->connection->insert($this->table, $this->queryOptions)
      ->fields($insert_fields);
    foreach ($this->insertValues as $insert_values) {
      $insert->values($insert_values);
    }
    $insert->execute();
  }
  catch (\Exception $e) {
    // One of the queries failed, rollback the whole batch.
    $transaction->rollback();

    // Rethrow the exception for the calling code.
    throw $e;
  }

  // Re-initialize the values array so that we can re-use this query.
  $this->insertValues = array();

  // Transaction commits here where $transaction looses scope.

  return TRUE;
}