Insert using Union/Union All fails to insert all rows - oracle

Question

I am trying to insert the result of a UNION into a table .While I cannot reproduce the original query here, due to it being in a restricted environment, it's structure looks similar to this:
WITH temp(X,Y,Z) AS(
SELECT....
)
SELECT X,Y,Z from TEMP --PART A
UNION
SELECT 'A','B','C' FROM DUAL;--PART B
Part A of the query returns about 1000 records, while Part B is just a single record.
When I wrap this whole query inside a procedure, such that the result of the select statements are inserted into a table, I see that only Part B, a single record gets inserted into the target table.Here is what it loos like when I wrap it inside the procedure.
CREATE OR REPLACE PROCEDURE PROC_INSERT
AS
BEGIN
INSERT INTO TABLENAME(COLUMN1,COLUMN2....)
WITH temp(X,Y,Z) AS(
SELECT....
)
SELECT X,Y,Z from TEMP
UNION
SELECT 'A','B','C' FROM DUAL;
COMMIT;
END;
I tried using both UNION and UNION ALL, but somehow I don't see to get the Part A of the result set inserted into the table.
What could be the possible reasons for such a scenario to occur? I tried to replicate the same ,but failed.

Answer 1

You can do something like this
DECLARE
CURSOR CUR IS SELECT X, Y, Z FROM OG_TABLE UNION SELECT 'A', 'B', 'C' FROM DUAL;
BEGIN
FOR REC IN CUR
LOOP
INSERT INTO NEWTABLE (COL1, COL2, COL3) VALUES (REC.X, REC.Y, REC.Z);
END LOOP;
END;
Alternative Optimized code
DECLARE
LIM PLS_INTEGER := 100;
CURSOR CUR IS SELECT X, Y, Z FROM OG_TABLE UNION SELECT 'A', 'B', 'C'
FROM DUAL;
TYPE OG_REC IS RECORD( X OG_TABLE.X%TYPE, Y OG_TABLE.Y%TYPE, Z
OG_TABLE%TYPE);
TYPE OGT IS TABLE OF OG_REC;
OG_TAB OGT;
BEGIN
OPEN CUR;
LOOP
FETCH CUR BULK COLLECT INTO OG_TAB LIMIT LIM;
BEGIN
FORALL i IN 1..OG_TAB.COUNT SAVE EXCEPTIONS
INSERT INTO NEWTABLE (COL1, COL2, COL3) VALUES (OG_TAB(i).X,
OG_TAB(i).Y, OG_TAB(i).Z);
EXCEPTION
WHEN OTHERS THEN
NULL;
END;
EXIT WHEN CUR%NOTFOUND;
END LOOP;
COMMIT;
CLOSE CUR;
END;