I have a PostgreSQL 7.1. When I start query like "SELECT * FROM table1 WHERE field1 = NULL;" it working OK, but query like "SELECT * FROM table1 WHERE field1 <> NULL" returns the void result. Field "field1" has type DATE. "... field1 IS NULL", "... field1 IS NOT NULL", "... field1 <> 0" also working correctly. "... field1 = 0" also not working.
With best regards, Serg Matskov.