Preventing duplicates

[joepineapples]

Hi All

I have two tables - Services and Performance.

Services is a list of Service details and Performance contains performance data on the Services. They are linked by the Service_ID.

The Performance table has fields for year and quarter. So, in theory, I can get an overview of how a service has performed over the quarters/years.

How can I prevent users creating duplicate entries when it comes to adding data to the performance table (In relation to Year & Quarter)?

Any help would be much appriciated.

 

[Dennisk]

If the data is entered through a form then you should validate in the before update event for the year and quarter.

But, you could create a unique compound key consisting of year and quarter, and let Access trap the duplicate.

 

[joepineapples]

Thanks Dennisk

I used the unique compound key idea.