Can I edit AutoNumber Column in Access?

Question

I've lost my data in Access base, and I've manage to bring them back but when I copy the values in the table with the AutoNumber Column it increments the numbers. Is there Any way to change it to int and then bring it back to AutoNumber?

Answer 1

Here is how I managed to do this in Access 2010:

1. Make a backup of your database. (Just to be safe.)
2. Right-click on the table in the tables list, and select Export->Excel. Accept all defaults.
3. Open the table in Excel and make the desired change to the autonumber field.
4. Open the table and delete all rows
5. Right-click on table in the tables list, and select Import->Excel
   • In the options, choose "Append to table" and select the table. Accept defaults for all other options

This might not be a viable solution for a large table. I don't think Excel can handle more than around 65K rows.

Answer 2

Don't copy the data with the user interface, but append it with a query. Because an Autonumber field is just a long integer with a special default value, you can append to it values that already exist. That doesn't work in the UI, but only in SQL.

An Autonumber field has a few other properties that are different from a normal Long Integer field, but in terms of appending data, those are not relevant. One of those properties is that it is not editable once it's populated, and another is that you can have only one in each table.