I have a customer table, tblCustomer. I get updated additional customers from the web in an Excel spread sheet. When new customers are added it is included with the previous customers so I need a way to prevent customers already in the database from being added since I would result in duplicate customers.

When I import these new customers how can I prevent adding customers that are already in the database?

Thanks

Don't import your data directly into tblCustomer. Import it into a temp table that has the same structure as tblCustomer. Make sure that in tblCustomer that Customer ID is a unique primary key.

After you import the data into a temp table, then use an append query to append the new data from the temp to tblCustomer. Because the Customer ID is a primary key set to INDEXED - NO DUPLICATES, Access will reject the duplicates based on Customer ID.

If your spreadsheet doesn't have Customer ID, then you'll have to create a unique key based on a combination of Last Name + First Name + Address or something like that.

Greg Serrano
Michigan Dept. of Environmental Quality, Air Quality Division