How to merge with multiple updates

Question

Hi All,
can someone help with merge and multiple updates when matched ?
create table foo
id number,
name varchar2(30),
col1 date,
col2 date
create table bar
id number,
name varchar2(30),
col1 date,
col2 date
insert into foo values ( 1, 'test1', sysdate + 30, sysdate);
insert into foo values ( 2, 'test2', sysdate + 30, sysdate);
insert into foo values ( 3, 'test3', sysdate + 30, sysdate);
MERGE INTO BAR T1
USING (SELECT id, NAME, col1, col2 FROM foo) T2
ON (T1.id = T2.id)
WHEN MATCHED THEN
UPDATE SET T1.NAME=T2.NAME where T1.Name != T2.Name
UPDATE SET T1.col1=T2.col1 where T1.col1 != T2.col1
UPDATE SET T1.col2=T2.col2 where T1.col2 != T2.col2
WHEN NOT MATCHED THEN
INSERT (ID, NAME, col1, col2 ) VALUES (t2.Id, t2.NAME, t2.col1, t2.col2);
Reason for having multiple updates to same row is i want to update the column only if name, col1, and col2 columns have changed. So, I want to first match by rows and then update the columns in bar that have changed in foo.
Any thoughts on how I might do this in merge ?. I get the foll. error
ERROR at line 6:
ORA-00933: SQL command not properly ended
Thanks
Vissu

Answer 1

I think you will be better off reading this link.
http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/statements_9016.htm#SQLRF01606
It will be something like this.
MERGE INTO BAR T1
USING (SELECT id, NAME, col1, col2 FROM foo) T2
ON (T1.id = T2.id)
WHEN MATCHED THEN
UPDATE SET T1.NAME=T2.NAME ,
                      t1.col1 = t2.col2 ,
                      t1.col2 = t2.col2
where T1.Name != T2.Name or t1.col1 != T2.col1 or t1.col2 != t2.col2
WHEN NOT MATCHED THEN
INSERT (ID, NAME, col1, col2 ) VALUES (t2.Id, t2.NAME, t2.col1, t2.col2);Please note this code is untested.
Regards
Raj