db_next_id

Return a new unique ID in the given sequence.

For compatibility reasons, Drupal does not use auto-numbered fields in its database tables. Instead, this function is used to return a new unique ID of the type requested. If necessary, a new sequence with the given name will be created.

Note that the table name should be in curly brackets to preserve compatibility with table prefixes. For example, db_next_id('{node}_nid');

Related topics

Database abstraction layer

Allow the use of different database servers using the same code base.

14 calls to db_next_id()

File

includes/database.mysqli.inc, line 245

Database interface code for MySQL database servers using the mysqli client libraries. mysqli is included in PHP 5 by default and allows developers to use the advanced features of MySQL 4.1.x, 5.0.x and beyond.

Code

function db_next_id($name) {
  $name = db_prefix_tables($name);
  db_query('LOCK TABLES {sequences} WRITE');
  $id = db_result(db_query("SELECT id FROM {sequences} WHERE name = '%s'", $name)) + 1;
  db_query("REPLACE INTO {sequences} VALUES ('%s', %d)", $name, $id);
  db_query('UNLOCK TABLES');

  return $id;
}