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pre postgres 15 can you solve this with two unique constraints ? unique (EmployeeName), unique (EmployeeName, CarID)
by jamesmstone 4y ago
pre postgres 15 can you solve this with two unique constraints ?
unique (EmployeeName),
unique (EmployeeName, CarID)
- masklinn 4y agoYou’d most likely solve this by making the CarID NOT NULL because there’s why would you even have a row with no useful data? And if this is your employee table, you’d have UNIQUE (EmployeeData) and UNIQUE (CarID), and it would do what you want.
- ryanbrunner 4y agoThat's not quite the same, since the previous solution of unique (EmployeeName, CarID) allowed for one employee to have 2 separate cars. You have to use conditional indexes to solve this.