When doing a MERGE in Oracle SQL, how can I update rows that aren't matched

Question

Hi,
create table TEST1
History_date Date,
ID NUMBER not null
create table TEST2
ID NUMBER not null,
History_date Date,
We_history_date Date
Can we do like this...
merge into test2 t2
using
test1 t1
ON (t1.id = t2.id)
when matched
update set t2.We_history_date = t1.history_date
when not matched
update set t2.We_history_date = NVL(t2.we_history_date,SYSDATE);Thanks,
Edited by: 960736 on Sep 27, 2012 2:05 PM

Answer 1

There is nothing to update if there is no match.
You need to INSERT a new record.
See the Examples section of the MERGE statement in the SQL Language doc
http://docs.oracle.com/cd/B28359_01/server.111/b28286/statements_9016.htm
>
Examples
Merging into a Table: Example The following example uses the bonuses table in the sample schema oe with a default bonus of 100. It then inserts into the bonuses table all employees who made sales, based on the sales_rep_id column of the oe.orders table. Finally, the human resources manager decides that employees with a salary of $8000 or less should receive a bonus. Those who have not made sales get a bonus of 1% of their salary. Those who already made sales get an increase in their bonus equal to 1% of their salary. The MERGE statement implements these changes in one step:
MERGE INTO bonuses D
USING (SELECT employee_id, salary, department_id FROM employees
WHERE department_id = 80) S
ON (D.employee_id = S.employee_id)
WHEN MATCHED THEN UPDATE SET D.bonus = D.bonus + S.salary*.01
DELETE WHERE (S.salary > 8000)
WHEN NOT MATCHED THEN INSERT (D.employee_id, D.bonus)
VALUES (S.employee_id, S.salary*.01)
WHERE (S.salary <= 8000);