Introduction
Defining columns with UNIQUE
Adding and removing UNIQUE constraints
Instruction
Excellent. Now we have the right table to do a little testing. Take a look at the exercise.
Exercise
As we mentioned previously, each pair of name-genre values must now be unique. Take your time and test that. Add a row where both values will be different, a row where one of them will be unique, and a row where both parts of the pair will be the same as in another row. See what happens each time.
