Return cursor variable in function

Question

I have three different sql queries already joined to diff tables, like query1 is made by joining 4 diff tables.
query1----select a,b,c,x from t1(set of 4 tables)
query2----select e,f from t2(set of 3 tables) where t1.x=t2.x
query3----select g,h from t3(set of 3 tables) where t1.x=t3.x
I need to return the resultset on a single row something like this_
a,b,c,x,e,f,g,h
I am using the above queries in a function and to return the result set using cursor variable as the return type for the function.
Please suggest a suitable solution design.
Thanks.

Answer 1

I have only single column in query1 which is referencing to query2 and query 3. So further joining them is not preferred. There is no escape from joining them. It will probably be the most effective solution.
That said you might consider to restructure/review your whole involved select(s).
Translating Laurents proposition to your nomenclature you could finally end up with something like
CREATE FUNCTION f (p_st your_data_type)
   RETURN sys_refcursor
AS
BEGIN
   OPEN cur FOR
      SELECT *
        FROM query1, query2, query3
       WHERE st = p_st AND query1.ID = query2.ID AND query1.ID = query3.ID;
   RETURN cur;
END;