>>When the user enters a new unit, or modifies the current one, I need to save it. But I don't want it to save if the unit is a duplicate. I also want to be the one to give the error message.
>>
>>Currently, I have a complicated IF to determine if the unit has changed and then I scan through the table to see if it's already there. I also have to make sure I don't get an error if the user changes the unit name, then changes it back, because then it will have changed AND be in the table already.
>>
>>It seems like there should be a simpler way of doing this. I've made the unit name a candidate index. Can I do the row update and have it tell me if the key's uniqueness was violated?
>>
>>Is there some way to put this in the database so whenever a user tries to save a duplicate unit, my error message comes up an the save is rejected?
>>
>>Thanks,
>>
>>-Michelle
>
>I think Candidate Tag is normal solution here.

Candidate Tag? Is that different than making a field a candidate key? If not, and since it's already a candidate key, I don't see how that's a solution...

Thanks,

-Michelle