By chx on
Change record status: 
Published (View all published change records)
Project: 
Drupal core
Introduced in branch: 
8.x
Issue links: 
https://www.drupal.org/node/813540
Description: 

In Drupal 7, $query->condition('field', NULL) matched rows when the field contained a NULL. However, as SQL (despite being called a relational database) is employing a 3VL, any logical operation on a NULL value results in NULL so this behavior is wrong. This is fixed in D8 and $query->condition('field', NULL) will never match anything. Use $query->isNull('field'); instead.

Impacts: 
Module developers