List the name of employees who had left the company? When were they hired?
employee that has left the company refers to EndDate is not null
SELECT T1.FirstName, T1.LastName, T2.HireDate FROM Person AS T1 INNER JOIN Employee AS T2 ON T1.BusinessEntityID = T2.BusinessEntityID INNER JOIN EmployeeDepartmentHistory AS T3 ON T2.BusinessEntityID = T3.BusinessEntityID WHERE T3.EndDate IS NOT NULL