PLS-00201 Error in Pipelined Function in PL/SQL - plsql

Question

I was trying to create a pipelined table function in PL/SQL but facing the below error. Is this an syntax error?
CREATE OR REPLACE FUNCTION FUNC_IDS(
IDS_IN IN VARCHAR2
) RETURN IDS_T
PIPELINED
IS
BEGIN
select * from dual;
return;
END func_ids;
Script Output:
Function FUNC_IDS compiled
LINE/COL ERROR
--------- -------------------------------------------------------------
0/0 PL/SQL: Compilation unit analysis terminated
3/10 PLS-00201: identifier 'IDS_T' must be declared
Errors: check compiler log
I missed to create the row and table types before creating the func. Have created them later as below and trying to create the function that gets input as a string of IDs and pipe out the individual IDs to another function.
CREATE TYPE TF_ROW AS OBJECT (ID NUMBER);
CREATE TYPE IDS_T IS TABLE OF TF_ROW;
create or replace function func_ids (ids_in in varchar2) return ids_t pipelined is
n_start pls_integer := 1;
n_end pls_integer := 1;
--
begin
loop
-- find the first and next comma in string
n_start := instr(ids_in, ',', n_start, 1);
n_end := instr(ids_in, ',', n_start, 2);
--
if (n_end <= 0) then
exit;
end if;
-- get the string and pipe it back out
pipe row (to_number(substr(ids_in, n_start+1, n_end - n_start - 1)));
-- ready for next one
n_start := n_end;
end loop;
return;
end func_ids;
Script Output:
Function FUNC_IDS compiled
LINE/COL ERROR
--------- -------------------------------------------------------------
22/5 PL/SQL: Statement ignored
22/15 PLS-00382: expression is of wrong type
Errors: check compiler log
What's wrong with the expression here?pipe row (to_number(substr(ids_in, n_start+1, n_end - n_start - 1)));

Answer 1

As you were told, IDS_T isn't declared.
Here's an example which works. See how I did it, do it yourself with your data.
Types:
SQL> create or replace type t_row is object (empno number, ename varchar2 (20));
2 /
Type created.
SQL> create or replace type t_tab is table of t_row;
2 /
Type created.
Function:
SQL> create or replace function func_ids (ids_in in varchar2)
2 return t_tab
3 pipelined
4 is
5 begin
6 for cur_r in (select empno, ename
7 from emp
8 where deptno = ids_in)
9 loop
10 pipe row (t_row (cur_r.empno, cur_r.ename));
11 end loop;
12
13 return;
14 end func_ids;
15 /
Function created.
Testing:
SQL> select * from table(func_ids (20));
EMPNO ENAME
---------- --------------------
7369 SMITH
7566 JONES
7788 SCOTT
7876 ADAMS
7902 FORD
SQL>
How to use the result returned by FUNC_IDS? I'm doing it using code you posted as a comment (the FUNC_ENAME function); I marked what you did wrong.
SQL> CREATE OR REPLACE FUNCTION func_ename (ids t_tab)
2 RETURN VARCHAR2
3 IS
4 l_tmp VARCHAR2 (100);
5 l_result VARCHAR2 (400);
6 BEGIN
7 l_result := ';';
8
9 FOR i IN ids.FIRST .. ids.LAST
10 LOOP
11 SELECT l.ename
12 INTO l_tmp
13 FROM emp l
14 WHERE l.empno = ids (i).empno; --> this line was wrong
15
16 l_result := l_result || l_tmp || ';';
17 END LOOP;
18
19 RETURN l_result;
20 END;
21 /
Function created.
SQL> SELECT func_ename (func_ids (10)) FROM DUAL;
FUNC_ENAME(FUNC_IDS(10))
------------------------------------------------------------------
;CLARK;KING;MILLER;
SQL>