Fine thanks,I've found that way : recettes=> DROP FUNCTION has_infos(text); DROP FUNCTION
recettes=> CREATE FUNCTION has_infos(text DEFAULT '') RETURNS boolean AS $BODY$ recettes$> BEGIN recettes$> IF character_length($1) > 0 THEN recettes$> RETURN TRUE; recettes$> ELSE recettes$> RETURN FALSE; recettes$> END IF ; recettes$> END recettes$> $BODY$ recettes-> LANGUAGE 'plpgsql' ; CREATE FUNCTION I've verified, it works on NULL input... 2012/11/7 David Johnston <pol...@yahoo.com> > On Nov 7, 2012, at 0:33, Yvon Thoraval <yvon.thora...@gmail.com> wrote: > > I'd like to create a function : > returning true if the length of the text arg is greater than 0 ; > false otherwise ; > > and also returning false when arg is NULL, then i wrote : > > CREATE FUNCTION has_infos(text) RETURNS boolean AS 'select > character_length($1) > 0;' LANGUAGE SQL IMMUTABLE RETURNS FALSE ON NULL > INPUT; > > where i get the error : > > ERROR: syntax error at or near "FALSE" > LINE 1: ...r_length($1) > 0;' LANGUAGE SQL IMMUTABLE RETURNS FALSE ON N... > > with "RETURNS NULL on NULL INPUT", that's OK. > > -- > Yvon > > > You have to allow for null input and deal with it in the function body. > Usually via a CASE structure. > > David J. > > -- Yvon
