I was trying this one:
ALTER TABLE MyTable ADD PRIMARY KEY Field1 + Field2 + Field3 tag pk
but I get....Operator/operand type mismatch. Field2 is char, but that's not would be trouble, well, I think.

Sorry by my ignorance, if I have this records...
Field1 Field2 Field3
----------------------------
4 5 1
3 1 6

it will be a duplicate key? (i.e. 4+5+1=10 and 3+1+6=10 too!!!)


Thanks a lot!!!