查询将从两个表返回非常见的empId

Question

我有两张表Employee和EmployeeAddress。我希望有一个查询可以从两个表中返回非常见的empId。

表的结构。

• Employee：EmpID和EmpName
• EmployeeAddress：EmpID和地址

Answer 1

NOT IN和UNION的组合应该

select empid
from employee
where empid not in (select empid from EmployeeAddress)
union select empid
from EmployeeAddress
where empid not in (select empid from employee)

Answer 2

一种方法是使用FULL OUTER JOIN

SELECT COALESCE(e.EmpID, ea.EmpID) AS EmpID
FROM   Employee e
       FULL OUTER JOIN EmployeeAddress ea
         ON e.EmpID = ea.EmpID
WHERE  e.EmpID IS NULL
        OR ea.EmpID IS NULL; 

Answer 3

Select * FROM (select empid from employee Except select empid from EmployeeAddress )A
UNION 
SELECT * FROM (select empid from EmployeeAddress Except select empid from employee)B