function Connection::nextId

Same name in this branch
  1. 8.9.x core/tests/fixtures/database_drivers/custom/fake/Connection.php \Drupal\Driver\Database\fake\Connection::nextId()
  2. 8.9.x core/lib/Drupal/Core/Database/Driver/sqlite/Connection.php \Drupal\Core\Database\Driver\sqlite\Connection::nextId()
  3. 8.9.x core/lib/Drupal/Core/Database/Driver/mysql/Connection.php \Drupal\Core\Database\Driver\mysql\Connection::nextId()
  4. 8.9.x core/lib/Drupal/Core/Database/Connection.php \Drupal\Core\Database\Connection::nextId()
Same name in other branches
  1. 9 core/modules/sqlite/src/Driver/Database/sqlite/Connection.php \Drupal\sqlite\Driver\Database\sqlite\Connection::nextId()
  2. 9 core/modules/mysql/src/Driver/Database/mysql/Connection.php \Drupal\mysql\Driver\Database\mysql\Connection::nextId()
  3. 9 core/modules/pgsql/src/Driver/Database/pgsql/Connection.php \Drupal\pgsql\Driver\Database\pgsql\Connection::nextId()
  4. 9 core/tests/fixtures/database_drivers/custom/fake/Connection.php \Drupal\Driver\Database\fake\Connection::nextId()
  5. 9 core/lib/Drupal/Core/Database/Connection.php \Drupal\Core\Database\Connection::nextId()
  6. 10 core/modules/sqlite/src/Driver/Database/sqlite/Connection.php \Drupal\sqlite\Driver\Database\sqlite\Connection::nextId()
  7. 10 core/modules/mysql/src/Driver/Database/mysql/Connection.php \Drupal\mysql\Driver\Database\mysql\Connection::nextId()
  8. 10 core/modules/pgsql/src/Driver/Database/pgsql/Connection.php \Drupal\pgsql\Driver\Database\pgsql\Connection::nextId()
  9. 10 core/tests/fixtures/database_drivers/custom/fake/Connection.php \Drupal\Driver\Database\fake\Connection::nextId()
  10. 10 core/lib/Drupal/Core/Database/Connection.php \Drupal\Core\Database\Connection::nextId()

Retrieve a the next id in a sequence.

PostgreSQL has built in sequences. We'll use these instead of inserting and updating a sequences table.

Overrides Connection::nextId

File

core/lib/Drupal/Core/Database/Driver/pgsql/Connection.php, line 348

Class

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

Namespace

Drupal\Core\Database\Driver\pgsql

Code

public function nextId($existing = 0) {
    // Retrieve the name of the sequence. This information cannot be cached
    // because the prefix may change, for example, like it does in simpletests.
    $sequence_name = $this->makeSequenceName('sequences', 'value');
    // When PostgreSQL gets a value too small then it will lock the table,
    // retry the INSERT and if it's still too small then alter the sequence.
    $id = $this->query("SELECT nextval('" . $sequence_name . "')")
        ->fetchField();
    if ($id > $existing) {
        return $id;
    }
    // PostgreSQL advisory locks are simply locks to be used by an
    // application such as Drupal. This will prevent other Drupal processes
    // from altering the sequence while we are.
    $this->query("SELECT pg_advisory_lock(" . self::POSTGRESQL_NEXTID_LOCK . ")");
    // While waiting to obtain the lock, the sequence may have been altered
    // so lets try again to obtain an adequate value.
    $id = $this->query("SELECT nextval('" . $sequence_name . "')")
        ->fetchField();
    if ($id > $existing) {
        $this->query("SELECT pg_advisory_unlock(" . self::POSTGRESQL_NEXTID_LOCK . ")");
        return $id;
    }
    // Reset the sequence to a higher value than the existing id.
    $this->query("ALTER SEQUENCE " . $sequence_name . " RESTART WITH " . ($existing + 1));
    // Retrieve the next id. We know this will be as high as we want it.
    $id = $this->query("SELECT nextval('" . $sequence_name . "')")
        ->fetchField();
    $this->query("SELECT pg_advisory_unlock(" . self::POSTGRESQL_NEXTID_LOCK . ")");
    return $id;
}

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