By mondrake on
Change record status: 
Published (View all published change records)
Project: 
Drupal core
Introduced in branch: 
11.5.x
Introduced in version: 
11.5.0
Issue links: 
https://www.drupal.org/node/3569137
Description: 

TRUNCATE's ::execute() method is currently returning an integer value, but that is fragile:

  /**
   * Executes the TRUNCATE query.
   *
   * In most cases, TRUNCATE is not a transaction safe statement as it is a DDL
   * statement which results in an implicit COMMIT. When we are in a
   * transaction, fallback to the slower, but transactional, DELETE.
   * PostgreSQL also locks the entire table for a TRUNCATE strongly reducing
   * the concurrency with other transactions.
   *
   * @return int|null
   *   Return value is dependent on whether the executed SQL statement is a
   *   TRUNCATE or a DELETE. TRUNCATE is DDL and no information on affected
   *   rows is available. DELETE is DML and will return the number of affected
   *   rows. In general, do not rely on the value returned by this method in
   *   calling code.
   *
   * @see https://learnsql.com/blog/difference-between-truncate-delete-and-drop-table-in-sql
   */
  public function execute() { ...

The Truncate class has now been changed to implement a new QueryExecutionVoidInterface that is ensuring ::execute not to return any value.

/**
 * General class for an abstracted TRUNCATE operation.
 */
class Truncate extends Query implements QueryExecutionVoidInterface {

...

  /**
   * Executes the TRUNCATE query.
   *
   * In most cases, TRUNCATE is not a transaction safe statement as it is a DDL
   * statement which results in an implicit COMMIT. When we are in a
   * transaction, fallback to the slower, but transactional, DELETE.
   * PostgreSQL also locks the entire table for a TRUNCATE strongly reducing
   * the concurrency with other transactions.
   *
   * @see https://learnsql.com/blog/difference-between-truncate-delete-and-drop-table-in-sql
   */
  public function execute(): void { ...
Impacts: 
Module developers