Andrius Glozeckas wrote: > I have a parent_type_id linking to group_type_id on the same table > (group_type). I am trying to get the groups with certain parent_type_id (be > it null or 17) and the number of their children in the same query: > > SELECT g1.*, COUNT(g2.*) > FROM group_type g1 LEFT JOIN group_type g2 ON g1.group_type_id = > g2.parent_type_id > WHERE g1.parent_type_id = null > GROUP BY g1.name, g1.type, g1.choice, g1.multiple, g1.self_ref, > g1.group_type_id, g1.parent_type_id > > But this doesn't give me any results, although there are a few records with > parent_type_id = null and one with 17.
This is not a bug. The correct syntax for testing for NULL is "column IS NULL". Do not use "column = NULL". -- Alvaro Herrera http://www.PlanetPostgreSQL.org/ "Changing the world ... one keyboard at a time!" (www.DVzine.org) ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
