hello

How to make the combination of three fields to be unique.

bye

geethanandh

thats quite a large question.

It despends on where the 3 fields come from? Why? When? etc.

Run a search on making unique serial numbers on this forum, its a never-ending discussion.

Do a search in FileMaker Inc's TechInfo Library for "validating calculation fields" it'll tell you how to do it. It works.

http://www.filemaker.com/

One way to do this would be to:

1. Create a stored calculating field (result type Text) called "CompositeKey" with a formula which concatenates your three fields, viz: Field1 & Field2 & Field3

2. Create a value list called "Unique Keys" which uses values from the "CompositeKey" field.

3. Validate each of the three data entry fields (Field1, Field2 and Field3) with the formula:

not PatternCount(ValueListItems("YourDBname.fp5", "Unique Keys"), CompositeKey)

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The result of this will be that although non-unique values will be able to be entered into the individual fields, values which combine with other values to generate a non-unique value in the 'CompositeKey' field will be rejected. You might want to consider making the validation strict and adding an appropriately informative custom message...