How can I stop the same record being saved twice

[Steve78]

Hi can anyone help please!

I'm writing a course registration Db. I have a have 3 tables at the moment tblContacts [ContactID], [FName], [SName], [Etc..] tblCourseRegistration[RegID] [ContactID][CourseID] and
tblCourses[CourseID] [CourseName] [Etc...]

These are all linked on a tabbed form. I have found that the same Contact can sign up for the same course twice. I need to stop this happening. Is there an easy way to prevent this or do I have to write a query that runs before the save command to prevent this?

Thanks in advance person with sore head!

 

[Steve78]

Thanks for that Pat it worked a treat! No more duplicates.

Just a small secondary issue, I was wondering whether it would be possible to replace the Access warning message with something a bit friendlier like -
"Sorry, you are already booked in for this course"
Is this possible?

 

[RuralGuy]

In your error handler just trap error 3022 and display your own message.

 

[Steve78]

Thanks for the advice RuralGuy could you just be a little more explicit or point me to a page that explains exactly how to do this.

Cheers

 

[RuralGuy]

You could put code in the OnError event of the form:

Private Sub Form_Error(DataErr As Integer, Response As Integer)

If DataErr = 3022 Then
   MsgBox "Sorry, this number has already been used!"
End If
Response = acDataErrContinue
End Sub

 

[Steve78]

Thanks for that I tried placing it on the OnError event of the form but it does not seem to work. I still get the same message. How do I find out what the error code is for a particular message?

 

[RuralGuy]

What code are you using to save the record?