Simple update statement problem

Question

hello experts sorry to bother everyone with such a mundane question but this is giving me a headache
i have 2 table ike and ike2
ike has c1, c2 and ike2 has c_1 and c_2
i like to set c2 on ike = to sysdate when c1=C_1
UPDATE (SELECT c1,c2,c_1, c_2 FROM ike , ike2  WHERE c1 = c_1 )
  SET ike.C2 = sysdate ;
this seems really simple todo yet im having a hell of a time getting this to work can anyone point out the obvious.
Please

Answer 1

Hi,
Let me make sure I understand.
Some rows in ike have matching rows in ike2; that is ike.c1 = ike2.c_1.
For those rows that have matches, you want to set ike.c2 to SYSDATE.
For the rows the don't have a match, you don't want to change anything.
Is that it?
If you wanted to change all the rows, you would just say:
UPDATE  ike
SET     c2 = SYSDATE;If you only want to update some of the rows in ike, you add a WHERE clause at the end.
Either an EXISTS or an IN sub-query would make a good condition. Here's how to use IN:
UPDATE  ike
SET     c2 = SYSDATE;
WHERE   c1  IN ( SELECT  c_1
                 FROM    ike2
               );