Unique Indexes

Show existing customers

First, let’s see the current customers table again.

Now, let’s execute the following command. This will try to create a new customer, John Boo, but with the identity value equal to the identity of an existing customer (that of John Woo).

We’re doing a business error on purpose here. We’ve inserted the new customer with the wrong identity. However, the query has been successfully executed, and the new customer has ...