Okay I have two tables VOUCHERT with the following fields ACTIVATIONCODE SERIALNUMBER VOUCHERDATADBID UNAVAILABLEAT UNAVAILABLEOPERATORDBID AVAILABLEAT AVAILABLEOPERATORDBID ACTIVATIONCODENEW EXT1 EXT2 EXT3 DENOMINATION -- I added this column into the table. and the second table is VOUCHERDATAT with the following fields VOUCHERDATADBID BATCHID VALUE CURRENCY VOUCHERGROUP EXPIRYDATE AGENT EXT1 EXT2 EXT3 What I want to do is copy the corresponding VALUE from VOUCHERDATAT and put it into DENOMINATION of VOUCHERT. The linking between the two is VOUCHERDATADBID. How do I go about it? It is not a 1:1 mapping. What I mean is there may be 1000 SERIALNUMBERS with a same VOUCHERDATADBID. And that VOUCHERDATADBID has only entry in VOUCHERDATAT, hence one value. Therefore, all serial numbers belonging to a certain VOUCHERDATADBID will have the same value. Will JOINS work? What type of JOIN should I use? Or is UPDATE table the way to go? Thanks for the help !!