ORA-06530: "Reference to uninitialized composite" even if initialized - oracle

Question

I have read solutions for solving the error but I don't know why still I get error,
CREATE OR REPLACE TYPE tmp_object IS OBJECT (
id NUMBER,
code NUMBER
);
CREATE OR REPLACE TYPE tmp_table IS TABLE OF tmp_object;
and the anonymous block to use them:
DECLARE
cnt PLS_INTEGER;
tmp_tbl tmp_table := tmp_table();
BEGIN
SELECT regexp_count('34, 87, 908, 123, 645', '[^,]+', 1) str
INTO cnt
FROM dual;
DBMS_OUTPUT.PUT_LINE('Counter is: ' || cnt);
FOR i IN 1..cnt
LOOP
tmp_tbl.EXTEND;
SELECT TRIM(REGEXP_SUBSTR('34, 87, 908, 123, 645', '[^,]+', 1,i)) str
INTO tmp_tbl(tmp_tbl.LAST).code
FROM dual;
DBMS_OUTPUT.PUT_LINE(tmp_tbl(i).code);
END LOOP;
END;
I use Oracle Database 12c and below is the error in SQL Developer 4.2:
Error report -
ORA-06530: Reference to uninitialized composite
ORA-06512: at line 14
00000 - "Reference to uninitialized composite"
*Cause: An object, LOB, or other composite was referenced as a
left hand side without having been initialized.
*Action: Initialize the composite with an appropriate constructor
or whole-object assignment.

Answer 1

The syntax that you are using works for RECORDs
SQL> set serverout on;
SQL>
SQL> DECLARE
2 cnt PLS_INTEGER;
3 l_code NUMBER;
4 TYPE tmp_object IS RECORD (
5 id NUMBER,
6 code NUMBER
7 );
8 TYPE tmp_table IS TABLE OF tmp_object;
9 tmp_tbl tmp_table := tmp_table();
10 BEGIN
11 SELECT regexp_count('34, 87, 908, 123, 645', '[^,]+', 1) str
12 INTO cnt
13 FROM dual;
14
15 DBMS_OUTPUT.PUT_LINE('Counter is: ' || cnt);
16
17 FOR i IN 1..cnt
18 LOOP
19 tmp_tbl.EXTEND;
20
21 SELECT TRIM(REGEXP_SUBSTR('34, 87, 908, 123, 645', '[^,]+', 1,i)) str
22 INTO tmp_tbl(tmp_tbl.LAST).code
23 FROM dual;
24 DBMS_OUTPUT.PUT_LINE(tmp_tbl(i).code);
25
26 END LOOP;
27 END;
28 /
Counter is: 5
34
87
908
123
645
PL/SQL procedure successfully completed
To use OBJECT, you have to use object constructor to insert into the table of that object
SQL>
SQL> CREATE OR REPLACE TYPE tmp_object IS OBJECT (
2 id NUMBER,
3 code NUMBER
4 );
5
6 /
Type created
SQL> CREATE OR REPLACE TYPE tmp_table IS TABLE OF tmp_object;
2 /
Type created
SQL>
SQL> DECLARE
2 cnt PLS_INTEGER;
3 tmp_tbl tmp_table := tmp_table();
4 BEGIN
5 SELECT regexp_count('34, 87, 908, 123, 645', '[^,]+', 1) str
6 INTO cnt
7 FROM dual;
8
9 DBMS_OUTPUT.PUT_LINE('Counter is: ' || cnt);
10
11 FOR i IN 1..cnt
12 LOOP
13 tmp_tbl.EXTEND;
14
15 SELECT tmp_object(i, TRIM(REGEXP_SUBSTR('34, 87, 908, 123, 645', '[^,]+', 1,i)))
16 INTO tmp_tbl(tmp_tbl.last)
17 FROM dual;
18
19 DBMS_OUTPUT.PUT_LINE(tmp_tbl(i).code);
20 END LOOP;
21 END;
22 /
Counter is: 5
34
87
908
123
645
PL/SQL procedure successfully completed
UPDATE: To open a cursor on the collection
You have to use a ref cursor to collect the value from the collection
using TABLE function and CAST function to help oracle identify the
datatype of the collection.
SQL> DECLARE
2 cnt PLS_INTEGER;
3 tmp_tbl tmp_table := tmp_table();
4 c_cursor SYS_REFCURSOR;
5 l_id NUMBER;
6 l_code NUMBER;
7 BEGIN
8 SELECT regexp_count('34, 87, 908, 123, 645', '[^,]+', 1) str INTO cnt FROM dual;
9
10 dbms_output.put_line('Counter is: ' || cnt);
11
12 FOR i IN 1 .. cnt LOOP
13 tmp_tbl.extend;
14
15 SELECT tmp_object(i, TRIM(regexp_substr('34, 87, 908, 123, 645', '[^,]+', 1, i)))
16 INTO tmp_tbl(tmp_tbl.last)
17 FROM dual;
18
19 END LOOP;
20
21 OPEN c_cursor FOR
22 SELECT * FROM TABLE(CAST(tmp_tbl AS tmp_table));
23 LOOP
24 FETCH c_cursor
25 INTO l_id,
26 l_code;
27 EXIT WHEN c_cursor%NOTFOUND;
28 dbms_output.put_line(l_id || ',' || l_code);
29 END LOOP;
30 CLOSE c_cursor;
31
32 END;
33 /
Counter is: 5
1,34
2,87
3,908
4,123
5,645
PL/SQL procedure successfully completed