I have two tables, one with old addresses of clients and one with new updated addresses. I know that a UNION join must be performed but I am unfamiliar with the syntax. Can someone help me out?

thx

A Google search provided the following link, which has a good description of the syntax and statement structure.
http://www.techonthenet.com/sql/union.php

Alternatively you can do one of three things.

Either of the tables is keyed you can Add the newer table to the older table and it will update the addresses in the old table.

You can run a query by example and link the customers tables then change the addresses in the older table to the addresses in the new table using the changeto command.

You can run a query joining both tables so you will have an old address and a current address, you may want to clean it up so that those tables with no new address have the current address copied over to the new address. Either of these is simple and can probably be done in less than a minute.