Still working to figure this stuff out :)
My question is, is it possible to set a combination of columns with a unique constraint?
ColumnA | ColumnB ----------------- Value1 | Value2 <- OK Value1 | Value1 <- OK Value2 | Value1 <- OK Value2 | Value2 <- OK Value1 | Value2 <- Not OK, combo already exists in the table
Any ideas? Or is this something that needs to be enforced in the logic layer?