Trigger Table

Question

<pre>
i have audit table as below
CREATE TABLE DS_JOB_LOG
JOB_ID NUMBER,
JOB_NAME VARCHAR2(200),
LOAD_DATE TIMESTAMP,
i am trying to write a trigger which does the job of inserting one sequence number kind of thing for the column JOB_ID in DS_JOB_LOG table.
Trigger should be fired when i insert the data into the columns JOB_NAME and LOAD_DATE .
Process: For every insert on the table it should create one new record and for any update(on JOB_NAME) it updates the row with just LOAD_DATE column
i am not strong at PLSQL could any one help me for this .
CREATE OR REPLACE TRIGGER TRIG_TEST
AFTER INSERT ON DS_JOB_LOG
FOR EACH ROW
BEGIN
UPDATE SCOTT.DS_JOB_LOG JOB_LOG
SET
JOB_LOG.JOB_ID = (
SELECT COALESCE(MAX(LG.JOB_ID),0) + 1
FROM SCOTT.DS_JOB_LOG LG
WHERE
LG.JOB_NAME=:new.JOB_NAME
END;
Regards
naren.

Answer 1

thanks for reply..
i have modified trigger code but trigger is created with error msg.
CREATE OR REPLACE TRIGGER TRIG_TEST
AFTER INSERT ON SCOTT.DS_JOB_LOG
FOR EACH ROW
BEGIN
UPDATE SCOTT.DS_JOB_LOG JOB_LOG
SET
JOB_LOG.JOB_ID = (
SELECT SCOTT.LOG_SEQ.NEXTVAL
FROM SCOTT.DS_JOB_LOG LG
WHERE
LG.JOB_NAME=:new.JOB_NAME
WHERE SCOTT.DS_JOB_LOG.JOB_NAME=:new.JOB_NAME
END;
i have created sequence
CREATE SEQUENCE SCOTT.LOG_SEQ
INCREMENT BY 1
START WITH 1
NOMAXVALUE
NOMINVALUE
NOCYCLE
CACHE 20
NOORDER
GO