db_next_id

• Drupal 4.6
• Drupal 4.7
• Drupal 5

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Definition

db_next_id($name)
includes/database.mysqli.inc, line 243

Description

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

Name	Description
Database abstraction layer	Allow the use of different database servers using the same code base.

Code

<?php
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;
}
?>