Re: Constraint that compares and limits field values

[Michael Fuhr <mike@xxxxxxxx>]

On Wed, Jan 25, 2006 at 10:51:23AM -0800, MargaretGillon@xxxxxxxxxxxxxx wrote:
> I am in version 7.3 and it will not let me cast, I get message "ERROR: 
> Cannot cast type boolean to integer". I will save this for when I upgrade.

You can create casts with CREATE CAST.

http://www.postgresql.org/docs/7.3/static/sql-createcast.html

Something like this should work:

CREATE FUNCTION bool2int(boolean) RETURNS integer AS '
SELECT CASE WHEN $1 THEN 1 ELSE 0 END;
' LANGUAGE sql IMMUTABLE STRICT;
 
CREATE CAST (boolean AS integer) WITH FUNCTION bool2int(boolean);

-- 
Michael Fuhr