Subject How to join table with proc ?
Author mohamed.banaouas
firebird 1.5

this statement generate error:
select b.boo_int, sp.int_out
from boo b join sp_twice(b.boo_int) sp on (1=1)

"The cursor identified in the update or delete statement is not
positioned on a row. no current record for fetch operation."

table boo: create table boo (boo_int integer);
proc sp_twice:
create procedure sp_twice(int_in integer) returns (int_out integer) as
begin int_out = int_in * 2; suspend; end

I know that it is possible to do it with sub-select but when a proc
returns many columns, it's usefull to catch them in the returned

thanks for any help.