You could use a COALESCE instead of a case statement for simple case like this. The below will treat a NULL as false and then when you do not it becomes true. So NULLS will be set to true UPDATE boolean_column SET boolean_column = NOT COALESCE(boolean_column, false) hope that helps, Regina -----Original Message----- From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] On Behalf Of Ivan Sergio Borgonovo Sent: Thursday, December 06, 2007 10:19 AM To: pgsql-general@xxxxxxxxxxxxxx Subject: Re: simple update on boolean On Thu, 06 Dec 2007 14:53:13 +0100 Cedric Boudin <cedric@xxxxxxxxxxxx> wrote: > > What if boolean_column is NULL? > > > > btw set bolean_column= not bolean_column works "as expected". > > > > template1=# select (not 't'::boolean),(not 'f'::boolean),(not > > NULL::boolean); > > > > ?column? | ?column? | ?column? > > ----------+----------+---------- > > f | t | > > (1 riga) > If it was null before it has to be null afterwards (IMHO). > If you don't want to have null, > take care of it somewhere else but not here. That is the "as expected" part. The "case" case, other than being more verbose, do more than what I would expect since all NULL are converted to t. template1=# select case when NULL then 'f'::boolean else 't'::boolean end; case ------ t (1 riga) -- Ivan Sergio Borgonovo http://www.webthatworks.it ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend ----------------------------------------- The substance of this message, including any attachments, may be confidential, legally privileged and/or exempt from disclosure pursuant to Massachusetts law. It is intended solely for the addressee. If you received this in error, please contact the sender and delete the material from any computer. ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
