 I used the example from the `addcustomer` error message to add, turns out I cannot add the customer. I assume it is because same number as someone else. Meanwhile, `adddriver` can have same phone number.  Suggestion: Further elaborate on constraints <!--session: 1648792893914-20ed97f6-c386-4fd1-a883-ce35edf6abdc--><!--Version: Web v3.4.2-->
I used the example from the
addcustomererror message to add, turns out I cannot add the customer.I assume it is because same number as someone else.
Meanwhile,
adddrivercan have same phone number.Suggestion: Further elaborate on constraints