Andrus wrote: >> I have a strange problem with the following condition in a SELECT: >> AND (("TableData" = "inDate") OR ("inDate" IS NULL)) >> >> it works perfectly when the input date in the function (inDate) matchs >> a date in the table, but it does not work when the parameter inDate is >> NULL. >> I recall the function with pgadmin writing NULL as paramater. >> It seems that ("inDate" IS NULL) never returns true, even when the >> parameter is null... >> What's wrong? > > Order is wrong, change it to >> AND (("inDate" IS NULL) OR ("TableData" = "inDate") ) > > PostgreSQL OR is not commutative if left operand evaluates to NULL. Seems to work here: select (true or null) as a, (null or true) as b, (null or false) as c, (false or null) as d; a | b | c | d ---+---+---+--- t | t | | (1 row) -- Richard Huxton Archonet Ltd -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general