Re: Update rows when in other table

"elziko" <elziko_at_NOTSPAMMINGyahoo.co.uk> wrote in message news:40b468a8$0$7727$afc38c87_at_news.easynet.co.uk...
> I have two tables TAB_A and TAB_B. I want to update COL_1 in TAB_A to a
> certain value but only for rows where the value COL_2 in TAB_A is also
found
> in COL_2 of TAB_B.

Try this instead:

 UPDATE tab_a a
 SET col_1 = 'NEWVALUE'
 WHERE EXISTS (SELECT 1

                                 FROM tab_b b
                                 WHERE a.col_2 = b.col_2)
                                 AND col_1 IS NULL;

It only references tab_a once rather than twice. Received on Wed May 26 2004 - 14:32:08 CEST