Procedure to execute dynamic DDL

Question

If I have table T below, and I need to create partitions based on the year (YR), but I need to create partitions for each quarter of the year. How can I write a procedure to do that?
WITH T AS
(SELECT 2001 YR FROM DUAL
UNION ALL SELECT 2002 YR FROM DUAL
select * From t;
Here is what I need to have executed as part of the procedure:
ALTER TABLE T ADD PARTITION (PARTITION P2001_01 VALUES LESS THAN (TO_DATE('2001-01-01', 'YYYY-MM-DD' ));
ALTER TABLE T ADD PARTITION (PARTITION P2001_02 VALUES LESS THAN (TO_DATE('2001-04-01', 'YYYY-MM-DD' ));
ALTER TABLE T ADD PARTITION (PARTITION P2001_03 VALUES LESS THAN (TO_DATE('2001-07-01', 'YYYY-MM-DD' ));
ALTER TABLE T ADD PARTITION (PARTITION P2001_04 VALUES LESS THAN (TO_DATE('2001-10-01', 'YYYY-MM-DD' ));
ALTER TABLE T ADD PARTITION (PARTITION P2002_01 VALUES LESS THAN (TO_DATE('2002-01-01', 'YYYY-MM-DD' ));
ALTER TABLE T ADD PARTITION (PARTITION P2002_02 VALUES LESS THAN (TO_DATE('2002-04-01', 'YYYY-MM-DD' ));
ALTER TABLE T ADD PARTITION (PARTITION P2002_03 VALUES LESS THAN (TO_DATE('2002-07-01', 'YYYY-MM-DD' ));
ALTER TABLE T ADD PARTITION (PARTITION P2002_04 VALUES LESS THAN (TO_DATE('2002-10-01', 'YYYY-MM-DD' ));

Answer 1

If you want to run alter command manually then you can simply avoid execute immediate and create one table function to print the alter command like below.
CREATE OR REPLACE TYPE nt_tab IS TABLE OF VARCHAR2(2000);
CREATE OR REPLACE FUNCTION func_addpartition
RETURN nt_tab
AS
v_nttab nt_tab := nt_tab();
v_entrydate DATE;
v_incr NUMBER := 0;
v_incr1 NUMBER := 0;
BEGIN
FOR i IN (SELECT TRUNC(entry_date,'YYYY') date_entry,TO_CHAR(TRUNC(entry_date,'YYYY'),'YYYY') part_date FROM t GROUP BY TRUNC(entry_date,'YYYY'))
  LOOP
   v_incr := v_incr+1;
   v_incr1 := v_incr1+1;
   v_nttab.EXTEND;
   v_nttab(v_incr1) := 'ALTER TABLE T ADD PARTITION (PARTITION P'||i.part_date||'_0'||v_incr||' VALUES LESS THAN (TO_DATE('||''''||i.date_entry||''''||','||'''DD-MON-YYYY'''||'));';
   v_entrydate := i.date_entry;
  FOR j IN v_incr..3
   LOOP
    v_incr := v_incr+1;
    v_incr1 := v_incr1+1;
    v_entrydate := ADD_MONTHS(v_entrydate,3);
    v_nttab.EXTEND;
    v_nttab(v_incr1) := 'ALTER TABLE T ADD PARTITION (PARTITION P'||i.part_date||'_0'||v_incr||' VALUES LESS THAN (TO_DATE('||''''||v_entrydate||''''||','||'''DD-MON-YYYY'''||'));';
   END LOOP;
v_incr := 0;
END LOOP;
RETURN v_nttab;
EXCEPTION WHEN OTHERS THEN
RAISE;
END;
SELECT * FROM TABLE(FUNC_ADDPARTITION);
OUTPUT:-
SCOTT@orcl>SELECT * FROM TABLE(FUNC_ADDPARTITION);
COLUMN_VALUE
ALTER TABLE T ADD PARTITION (PARTITION P2001_01 VALUES LESS THAN (TO_DATE('01-JAN-01','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2001_02 VALUES LESS THAN (TO_DATE('01-APR-01','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2001_03 VALUES LESS THAN (TO_DATE('01-JUL-01','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2001_04 VALUES LESS THAN (TO_DATE('01-OCT-01','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2003_01 VALUES LESS THAN (TO_DATE('01-JAN-03','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2003_02 VALUES LESS THAN (TO_DATE('01-APR-03','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2003_03 VALUES LESS THAN (TO_DATE('01-JUL-03','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2003_04 VALUES LESS THAN (TO_DATE('01-OCT-03','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2006_01 VALUES LESS THAN (TO_DATE('01-JAN-06','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2006_02 VALUES LESS THAN (TO_DATE('01-APR-06','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2006_03 VALUES LESS THAN (TO_DATE('01-JUL-06','DD-MON-YYYY'));
ALTER TABLE T ADD PARTITION (PARTITION P2006_04 VALUES LESS THAN (TO_DATE('01-OCT-06','DD-MON-YYYY'));
12 rows selected.