Hi Why is '' not considered null is postgres (8.1.3) Currently I have to use the following workaround where I have zero length strings in char fields. select * from security.users where length(us_username)=0; Surely this a null. Apparently not in Postgres. Currently I have to use the following SQL to pick up zero length strings: alter table security.users add constraint notnull_username check(us_username <> ''); Thanks Gustav ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org/