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SQL Constraints

Introduction
Defining columns with UNIQUE
Adding and removing UNIQUE constraints
Summary

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.