Delete query using inner join

Question

I need to delete records from a table using inner join from other tables. See below for the table structure and records.
CREATE TABLE STUDENT (ROLL_NO NUMBER(10),NAME VARCHAR2(100),DEPT_NO NUMBER(10),JOIN_DATE DATE);
CREATE TABLE DEPART (DEPT_NO NUMBER(10), DEPT_NAME VARCHAR2(100));
CREATE TABLE ACTIVE_DEPT (DEPT_NO NUMBER(10), IS_ACTIVE VARCHAR2(1));
INSERT INTO STUDENT (ROLL_NO,NAME,DEPT_NO,JOIN_DATE) VALUES(1,'SAM',10,SYSDATE-10);
INSERT INTO STUDENT (ROLL_NO,NAME,DEPT_NO,JOIN_DATE) VALUES(2,'ALEX',10,SYSDATE -10);
INSERT INTO STUDENT (ROLL_NO,NAME,DEPT_NO,JOIN_DATE) VALUES(3,'FRANK',20,SYSDATE -10);
INSERT INTO STUDENT (ROLL_NO,NAME,DEPT_NO,JOIN_DATE) VALUES(4,'WAYNE',20,SYSDATE+1);
INSERT INTO STUDENT (ROLL_NO,NAME,DEPT_NO,JOIN_DATE) VALUES(5,'KRUL',30,SYSDATE -10);
INSERT INTO STUDENT (ROLL_NO,NAME,DEPT_NO,JOIN_DATE) VALUES(6,'ALICE',40,SYSDATE -10);
INSERT INTO DEPART (DEPT_NO,DEPT_NAME) VALUES (10,'DEPT1');
INSERT INTO DEPART (DEPT_NO,DEPT_NAME) VALUES (20,'DEPT2');
INSERT INTO DEPART (DEPT_NO,DEPT_NAME) VALUES (30,'DEPT3');
INSERT INTO ACTIVE_DEPT (DEPT_NO,IS_ACTIVE) VALUES (10,'Y');
INSERT INTO ACTIVE_DEPT (DEPT_NO,IS_ACTIVE) VALUES (20,'N');
INSERT INTO ACTIVE_DEPT (DEPT_NO,IS_ACTIVE) VALUES (30,'Y');
DELETE FROM STUDENT WHERE (STUDENT.DEPT_NO) IN (SELECT D.dept_no FROM DEPART D,ACTIVE_DEPT AD WHERE D.DEPT_NO = AD.DEPT_NO AND AD.IS_ACTIVE = 'N');The above delete query will delete two records from the STUDENT table. Now i want to include another condition say, join_date should be a past date (join_date < trunc(sysdate)).
How to include this condition in the above delete statement. I know i can do this using a subquery but i wont prefer that option. Basically i don't have much idea about join in delete statements.
Please help.

Answer 1

Is this you need ?
DELETE FROM student WHERE join_date < TRUNC(SYSDATE)
                                        AND student.dept_no IN (SELECT D.dept_no
                                                                  FROM depart d,active_dept ad
                                                                 WHERE d.dept_no = ad.dept_no AND ad.is_active = 'N');Only one record is deleted. -> 3,'FRANK',20,SYSDATE -10
>
Balaji      wrote:
Yes. But here we are getting the dept_no from the sub query, is there a better way to achieve this without sub query?
>
As far I know you need to have sub query in this case.
You can close this thread if answered. If you have any further queries please post it so that someone can help you.
Edited by: Lokanath Giri on २० मार्च, २०१२ ५:०५ अपराह्न