I stucked in some silly thing but...
I have a table where a have tree main fields where the combination of the tree can not be repeated.
Field 1: name
Filed 2: group
Field 3: sub_group
I have set a control field where i set it: name & group & sub_group
The option on the field definition, UNIQUE VALUE, does not work i think because i have set the field 1, 2 or 3 that can be empty. ???
What should be the steps to do by script and the trigger to do so validation ?