PL/SQL stored function return with row type - sql

Question

CREATE OR REPLACE FUNCTION lab( f_name IN VARCHAR2 )
RETURN test%ROWTYPE
IS
total NUMBER := 0;
CURSOR c_app IS
SELECT count(*),LISTAGG(s.sname,',') WITHIN GROUP (ORDER BY s.sname)
FROM APPLICANT a INNER JOIN SPOSSESSED s ON a.A# = s.A#
WHERE a.fname = f_name;
rec_app c_app%ROWTYPE;
BEGIN
OPEN c_app;
LOOP
FETCH c_app into rec_app;
EXIT WHEN c_app%NOTFOUND;
END LOOP;
CLOSE c_app;
RETURN rec_app;
END lab;
/
Fail to compile with errors that expression wrong type?
Isn't it possible to return with rowtype result?
for example i run this function
select lab(fname) from position where fname='PETER';
so the result will be display like
PETER : aaaa,bbbb,cccc

Answer 1

You're declaring the return as test%rowtype, then trying to return rec_app, which is declared as c_app%rowtype - so the types don't match. You can't do that.
c_app is only in scope within this function so it would not have any meaning for any callers, and you can't use it as the return type. You can return something that is actually test%rowtype, assuming test is a table, but not an arbitrary different type. It isn't clear that there is any relationship at all between your cursor and its row type, and the test table.
You're also looping round to potentially fetch multiple rows, but only returning the last one (or trying to, anyway), which probably isn't what you mean to do.
The simplest way to get all the cursor rows back to the caller is with a ref cursor:
CREATE OR REPLACE FUNCTION lab( f_name IN VARCHAR2 )
RETURN SYS_REFCURSOR
IS
ref_cur SYS_REFCURSOR;
BEGIN
OPEN ref_cur FOR
SELECT count(*),LISTAGG(s.sname,',') WITHIN GROUP (ORDER BY s.sname)
FROM APPLICANT a INNER JOIN SPOSSESSED s ON a.A# = s.A#
WHERE a.fname = f_name;
RETURN ref_cur;
END lab;
/
If you create an external type you could use PIPELINED but that doesn't appear necessary here. neither is quite using a %rowtype though. You can only return a %rowtype if you have a table that has the columns you want to return.