Question

我有两张桌子。我试图加入下面两个表的样本，表1引用表2两次。例如，如果我查看表1：组2和成员7，它应该在表2中查找ID并给出一个输出：

Group Members Name   Name
  2      7     Blue   Dog

表1

Group  Members
 2       7
 3       8
 5       10

表2

 ID     Name
 1      Green
 2      Blue
 3      Yellow
 4      Orange
 5      Red
 6      Elephant
 7      Dog
 8      Cat
 9      Chicken
 10     Mouse

任何建议？感谢

Answer 1

SELECT
  Table_1.*,
  g.Name,
  m.Name
FROM
  Table_1
  INNER JOIN Table_2 AS g ON Table_1.Group=g.ID
  INNER JOIN Table_2 AS m ON Table_1.Group=m.ID
WHERE
  Table_1.Group=2
  AND Table_1.Member=7

Answer 2

在不同的列上两次加入表2。

SELECT t1.*, t2.name AS group_name, t3.name AS member_name
FROM Table1 AS t1
JOIN Table2 AS t2 ON t1.group = t2.id
JOIN Table2 AS t3 ON t1.members = t3.id

Answer 3

很难从该描述中确切地说出您需要的内容，但是表格的别名可能就是您所需要的。它的工作原理如下：

SELECT t1.x, t2_1.y, t2_2.z
FROM table1 AS t1
JOIN table2 AS t2_1 ON t1.whatever = t2_1.whatever
JOIN table2 AS t2_2 ON t1.whatever = t2_2.whatever
...

MYSQL：如何在引用同一个表两次的同一查询上加入两个表

3 个答案: