Make Table and update without adding duplicates

[Tcurtis]

Good Morning! I have a question about creating a table from two different tables without adding duplicate information. I have two tables that will contain some of the same information but not all. There will only be a few duplicates but I want to be sure that they are not in the new table. How can I update the new table without bringing over duplicates?

Thank

 

[Joe4]

It really depends on how you are defining a "duplicate" record. Do all fields have to be the same, or just some key ones?

If you have a "key" field that must be unique, the easiest thing is to make the field a Primary Key field in your new table. Then it will not allow you to enter duplicates records based on this (the first one will add and all duplicates will fail).

If you are including ALL fields when determining if a record is a duplicate, then you can join both tables together in a UNION query. By default, I believe that UNION queries combine all duplicates. Then you can use this UNION query in your Append or Make Table Query (however you are building your new table).

 

[Tcurtis]

Perfect, thanks. I do have a primary key field that are job numbers. These are unique for each record. I really appreciate the help.