如何使用加入

Question

我有像

这样的表格

id       |  name     | manager
1        |  A        |    0 
2        |  B        |    1
3        |  C        |    2
4        |  D        |    1

我想要每个员工姓名以及经理姓名和身份证。

Answer 1

http://sqlfiddle.com/#!9/438dd7/2

SELECT e.*,
        e1.name
FROM employee e
LEFT JOIN employee e1
ON e.manager = e1.id

Answer 2

假设您的表名是员工和经理

SELECT 
e.id, 
e.name AS empname, 
m.name AS managername
FROM employee AS e 
INNER JOIN manager AS m ON e.manager = m.id

希望它能帮到你