We deal with mobile phones and this is just an example, but I would want to select the row that has the exact prefix of 07769 (prefix_id is 1), and not 0776 or 077, where the phone number is 07769666644, or select the row with prefix of 077(prefix_id is 5) where phone number is 07743211111. Unfortunately we are using a third party application and it won't allow pl/sql (procedures etc), we can only use sql. Thanks.