When entering a record, can I format a field so that the entered information (in this case it happens to be a part number) cannot be a duplicate of an existing entry in that particular field? If so how? Null entries must be permissable however.
(NB The purpose being to avoid someone duplicating an entry at some point in the future.)
Thanks.

Hi Steve,

Thanks for the question.

One way of restricting duplicates is in the design view of the table click into the field you want to restrict. In the Field Properties section make sure the General tab is highlighted and use the Index option at the bottom, change the Index to Yes (No Duplicates). This will flag up a problem if you want to keep entering 0, you could try setting the Required field to "No" and not entering any data instead of putting a 0.
Tracy