Few Queries

Hi ,

I'm still facing few problems and hence the query . I have searched the archives as well as read the manual.

1. I 'm firing a query and it returns the value in variable which I need to pass to other query . Is this a right way to pass the value ? I'm newbie to this Database and hence facing lot of syntax problems.

CREATE FUNCTION del_old_history() RETURNS bool AS '
declare
var_history_age_limit int4;
set_time datetime;
BEGIN
select into var_history_age_limit history_age_limit from database_info;
IF (var_history_age_limit is not null) THEN
set_time := select current_date()+ INTERVAL ' ' $var_history_age_limit day' ';

--begin transaction
delete from history where complete_time <= set_time;
END IF;

return true;
END;'
LANGUAGE 'plpgsql';

I get this error :
Error: ERROR: parser: parse error at or near "select"

NOTICE: Error occurred while executing PL/pgSQL function del_old_history

NOTICE: line 8 at assignment

2. Is there any equiavlent of MS -SQLServer 'trancount ' in postgres ?

3. if object_id ('database_info') is null

how is above statement verified in postgres . I tried looking for OID .

Any help will be highly appreciated.

Regards,
-Sugandha