Hello! Simon Green wrote:
>What I am trying to do in MySQL. > >Table1 > >UserID ProductID Old_UserID >1 2 4 >2 3 5 > >Table2 >UserID ProductID >4 Null >5 Null > >Table1 has new correct data. >Table2 has old incorrect data. >The link is Table2.UserID and Old_UserID > >What I need to do is update Table 2 with the new data from Table 1, >But I can not get this to work..e.g. > >UPDATE Table2.ProductID >SET Table2.ProductID = Table1.ProductID >WHERE Table1.Old_UserID = Table2.UserID > >REPLACE will not work as these are not KEY fields. >Once I have done the ProductID I should then be able to do the UserID using >the ProductID (as all values in one table are unique). > > SELECT concat('UPDATE Table2 SET ProductID = ', t1.ProductID, ' WHERE UserID = ', t1.UserID, ';' ) INTO OUTFILE '/tmp/update.sql' FROM Table1 t1 LEFT JOIN Table2 t2 ON (t1.Old_UserID = t2.UserID) WHERE t2.UserID IS NOT NULL ; \. /tmp/update.sql This might help...but better take a look at /tmp/update.sql, before executing it!!! Greetings Ralf -- Ralf Narozny SPLENDID Internet GmbH & Co KG Skandinaviendamm 212, 24109 Kiel, Germany fon: +49 431 660 97 0, fax: +49 431 660 97 20 mailto:[EMAIL PROTECTED], http://www.splendid.de --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php