SQL，获取外键值。外键引用同一个表

Question

MS SQL Server数据库。

我有这个简单的结构:(抱歉主键不在正确的位置）

在TEACHER表中我有一个外键“Chief”，它引用了TEACHER.ID（同一个表）。在进行SELECT查询时，我怎么能得到一个整数（Teacher.ID），而不是一个Chief的名字（TEACHER.Name for Chief）？

这个只得到一个整数（酋长的ID）：

SELECT DEPARTMENT.Name, TEACHER.Name, TEACHER.IDCode, POST.Name, TEACHER.Tel, TEACHER.Salary, TEACHER.Rise, TEACHER.HireDate, Chief
FROM TEACHER, DEPARTMENT, POST
WHERE TEACHER.ID_Post = POST.ID AND
    TEACHER.ID_Department = DEPARTMENT.ID;
GO

Answer 1

再次{p> JOIN TEACHER表，如下所示：

SELECT 
  d.Name, 
  t.Name, 
  t.IDCode, 
  p.Name, 
  t.Tel, 
  t.Salary, 
  t.Rise, 
  t.HireDate, 
  chief.Name 'Chief Name'
FROM TEACHER t 
INNER JOIN TEACHER chief ON t.Chief = chief.ID
INNER JOIN DEPARTMENT d ON t.ID_Department = d.ID
INNER JOIN POST p ON t.ID_Post = p.ID;

并使用ANS-SQL-92 JOIN语法而不是您在查询中使用的旧语法。 They are the same，但这是推荐的语法。

Answer 2

这应该有效：

SELECT DEPARTMENT.Name, TEACHER.Name, TEACHER.IDCode
    , POST.Name, TEACHER.Tel, TEACHER.Salary, TEACHER.Rise, TEACHER.HireDate, c.Name as ChiefName
    FROM TEACHER
    join DEPARTMENT on TEACHER.ID_Department = DEPARTMENT.ID
    Join POST on TEACHER.ID_Post = POST.ID
    Left Join TEACHER c on c.ID=TEACHER.Chief