Microsoft Office Tutorials and References
In Depth Information
By enforcing a relationship between the Sales and Customers lists, this means that if there is a
customer record in the Customers list that an item in the Sales list is using in its lookup field, then you
shouldn’t be able to delete it.
If you try it, the Delete button or menu item will not be grayed out, but it will fail with the
following message: “This item cannot be deleted because an item in the [Lookup] list is related to an item
in the [Source] list.”
If you had enabled cascading delete, then if you deleted a list item in the source list, the records in
the lookup or related list (like this one) would simply be deleted.
9. Keep all other defaults, and click OK.
10. As expected, you will be prompted to accept that enforcing that relationship behavior
will require the field to be index. Click OK to accept.
TITLE LENGTH TOO LONG?
You will notice that the generated field titles are a little lengthy, with the lookup field name, a
colon, and then the additional field name. If the field titles take up too much space, you can select
the column on the List Settings page and edit its title to make it more to your liking.
You can also see on the Change Column page that it indicates what list and what field in that list
the column pulls from.