Raymond O'Donnell wrote: > On 04/05/2007 21:34, Scott Ribe wrote: > > >Just discovered (the hard way) that casting a boolean column ::varchar > >doesn't work. I assume I can add a function somewhere that will define a > >default cast for this? Are there any other standard types that can't be > >cast > > I just use something like this: > > create or replace function bool2str(TheValue boolean) > returns varchar as > $$ > begin > if TheValue then > return 'true'; > else > return 'false'; > end if; > end; > $$ > language plpgsql stable; To complete the example, alvherre=# create cast (boolean as varchar) with function bool2str(bool); CREATE CAST alvherre=# select 't'::boolean::varchar; varchar --------- true (1 fila) Though I'd mark the function immutable rather than stable. alvherre=# select 'f'::boolean::varchar; varchar --------- false (1 fila) alvherre=# select '0'::boolean::varchar; varchar --------- false (1 fila) alvherre=# select '123'::boolean::varchar; ERROR: invalid input syntax for type boolean: "123" -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc.
