function Connection::nextId

File

core/modules/sqlite/src/Driver/Database/sqlite/Connection.php, line 452

Class

Connection

SQLite implementation of \Drupal\Core\Database\Connection.

Namespace

Code

public function nextId($existing_id = 0) {
  try {
    $this->startTransaction();
  } catch (\PDOException $e) {
    // $this->exceptionHandler()->handleExecutionException()
    // requires a $statement argument, so we cannot use that.
    throw new DatabaseExceptionWrapper($e->getMessage(), 0, $e);
  }
  // We can safely use literal queries here instead of the slower query
  // builder because if a given database breaks here then it can simply
  // override nextId. However, this is unlikely as we deal with short strings
  // and integers and no known databases require special handling for those
  // simple cases. If another transaction wants to write the same row, it will
  // wait until this transaction commits.
  $stmt = $this->prepareStatement('UPDATE {sequences} SET [value] = GREATEST([value], :existing_id) + 1', [], TRUE);
  $args = [
    ':existing_id' => $existing_id,
  ];
  try {
    $stmt->execute($args);
  } catch (\Exception $e) {
    $this->exceptionHandler()
      ->handleExecutionException($e, $stmt, $args, []);
  }
  if ($stmt->rowCount() === 0) {
    $this->query('INSERT INTO {sequences} ([value]) VALUES (:existing_id + 1)', $args);
  }
  // The transaction gets committed when the transaction object gets destroyed
  // because it gets out of scope.
  return $this->query('SELECT [value] FROM {sequences}')
    ->fetchField();
}