SQL，获取外键值。外键引用同一张表

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)。在执行 SELECT 查询时，如何获得不是整数(Teacher.ID)，而是酋长姓名(TEACHER.Name for Chief)？

这个只有一个整数(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

JOIN TEACHER 表再次，像这样:

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。