Josh Berkus <josh@agliodbs.com> writes:
>> How can i create a function that accept and return any type. the type "any"
>> is not allowing as parameter or return type. Is it possible? i want to
>> create a function similar to NULLIF().
> You can't, nor will you be able to -- in te future, some 7.4 functions will be
> able to *accept* any type, but they will still return a specific type.
Au contraire. The 7.4 polymorphic-function features may well solve
jinujose's problem, if he can indeed write a type-independent function
body. For example
create function nullif(anyelement, anyelement) returns anyelement as
'select case when $1 = $2 then null else $1 end' language sql;
I'm not sure we're all the way there yet, cf
http://archives.postgresql.org/pgsql-general/2003-09/msg00500.php
regards, tom lane