MS Access Form alpha numeric fields

Question

I have a field on an MS Access form that has the following validation rule:

Is Null Or Between 10000000 And 99999999

This basically restricts to the user to be able to enter 8 digits only.

Is there a way to change the validation rule so that the user can enter 8 alpha numeric characters?

Answer 1

Set the ValidationRule property on the field to

Is Null Or Like "????????"

Answer 2

One way to enforce this within the user interface would be via an input mask instead of validation:

AAAAAAAA

Update: As @Chris Rolliston points out, you are better off using validation at the database level to ensure you maintain valid data. How you do that will vary depending on the db engine (MS Access, SQL Server, Oracle, MySQL, PostgreSQL, etc.) where the table physically resides.

Answer 3

You can put VBA in the AfterUpdate event of the object like:

If len(Trim(Me.MyTextField)) <> 8 then
  Msgbox "Please enter an 8-digit key"
  Me.MyTextField = ""
End If

Make sure the Trim function is in there to eliminate the user trying to add empty spaces.