DCount to check multiple fields for duplicates? Am I Crazy

[mrmims]

Am I right in thinking I can use DCount in the following way?



I have a Table for storing Products using Material, Manufacturer, and Vendor. A Product may have many different combinations of these three Fields. For example Baking Soda made by Arm & Hammer sold by Costco ... or Baking Soda made by Kroger sold by Smiths ... and on and on.

I need to create a line of code which will check, as I enter new products, my 3 fields (MaterialID, ManuID, and VendorID) to insure I do not have a duplicate combination of those fields.

I don't understand where to begin with a DCount ...

Thank you for you help

[ssanfu]

I would set a unique index instead of using code. Setting an index on those 3 field will not allow a duplicate entry.

[mrmims]

That works even better! And much cleaner without code.

Thank you