How to Display and Hide Autonumber Fields in Access 2010 Forms

The following is an excerpt from an appendix for Office 2010: The Missing Manual. It covers the AutoNumber (unique ID) field in Access 2010.

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As you already know, the best way to uniquely identify each record in a table is with an AutoNumber field. When you insert a record into a table that has an AutoNumber field, Access automatically fills in a value for that field. All the tables you'll see in this book include a field named ID that uses the AutoNumber data type.

Only Access can set an AutoNumber field. For that reason, you may not want to show it in your forms. (If you decide not to show it, just select it in Layout view and then press Delete.) However, there are some reasons that you might actually want to keep the AutoNumber field on display:

• You use the AutoNumber field on some type of paperwork. Cacophoné Studios puts each student’s ID number on their registration papers. When you need to look up the student record later on, it’s easier to use the ID number than search by name.
  
  
• You use the AutoNumber field as a tracking value or confirmation number. After you enter a new order record in the Boutique Fudge database, you can record the order record’s ID number. The next time you have a question about the order (has it shipped?), you can use the ID number to look it up.

Depending on how you use the ID number, you may choose to place it at the bottom of the form rather than in its usual position at the top. That approach avoids confusion. (It’s less likely that people will try to type in their own ID numbers when they create new records.)