列出员工姓名和主管姓名。
CREATE TABLE Employees (
EmployeeID char(4) PRIMARY KEY,
EmployeeName varchar(30) NOT NULL,
HourlyRate real,
SkillType varchar(20),
SupervisorID char(4) NOT NULL
)
所以我想还一张表
Employee Name || Supervisor Name
我试过了
Select
EmployeeName,
(Select EmployeeName Where SupervisorID = EmployeeID) As Supervisor
From Employees
但是它只显示值,其中Employee
是他们自己的监控器,而其他值则返回null。我一定是错过了一些简单的东西,但我想不出来。
发布于 2014-04-10 15:52:23
您需要再次加入同一个表。
Select e.EmployeeName, s.EmployeeName As Supervisor
From Employees e
left join Employees s on s.employeeID = e.supervisorID
发布于 2014-04-10 15:54:28
SELECT EMAIN.EmployeeName AS Employee,
(SELECT E.EmployeeName FROM Employees AS E WHERE EMAIN.EmployeeID = E.SupervisorID) AS Supervisor
FROM Employees AS EMAIN
https://stackoverflow.com/questions/22992920
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