如何在MySQL中加入这些数据？

如果我有这样一张桌子：

表格A

：

id| object | type
1 | greg | person
2 | mary | person
3 | jared | person
4 | kelly | person
5 | melissa | person
6 | william | person
7 | skiing | hobby
8 | biking | hobby

id | husband | wife
1 | greg | mary
2 | jared | kelly
3 | william | kelly

id | female | hobby
1 | mary | skiing
2 | kelly | biking

id | a | b | link
1 | 1 | 2 | related
2 | 3 | 4 | related
3 | 6 | 4 | related
4 | 1 | 4 | related
5 | 2 | 7 | likes
6 | 4 | 8 | likes

表B

：

id| object | type
1 | greg | person
2 | mary | person
3 | jared | person
4 | kelly | person
5 | melissa | person
6 | william | person
7 | skiing | hobby
8 | biking | hobby

id | husband | wife
1 | greg | mary
2 | jared | kelly
3 | william | kelly

id | female | hobby
1 | mary | skiing
2 | kelly | biking

id | a | b | link
1 | 1 | 2 | related
2 | 3 | 4 | related
3 | 6 | 4 | related
4 | 1 | 4 | related
5 | 2 | 7 | likes
6 | 4 | 8 | likes

表C

：

id| object | type
1 | greg | person
2 | mary | person
3 | jared | person
4 | kelly | person
5 | melissa | person
6 | william | person
7 | skiing | hobby
8 | biking | hobby

id | husband | wife
1 | greg | mary
2 | jared | kelly
3 | william | kelly

id | female | hobby
1 | mary | skiing
2 | kelly | biking

id | a | b | link
1 | 1 | 2 | related
2 | 3 | 4 | related
3 | 6 | 4 | related
4 | 1 | 4 | related
5 | 2 | 7 | likes
6 | 4 | 8 | likes

是否有办法获得以下结果表：

表格

：

id| object | type
1 | greg | person
2 | mary | person
3 | jared | person
4 | kelly | person
5 | melissa | person
6 | william | person
7 | skiing | hobby
8 | biking | hobby

id | husband | wife
1 | greg | mary
2 | jared | kelly
3 | william | kelly

id | female | hobby
1 | mary | skiing
2 | kelly | biking

id | a | b | link
1 | 1 | 2 | related
2 | 3 | 4 | related
3 | 6 | 4 | related
4 | 1 | 4 | related
5 | 2 | 7 | likes
6 | 4 | 8 | likes

仅使用MySQL查询（/ies）

• 逻辑基本上从表B和表B的所有行开始迭代
• 当所选表格为

  TableB

  时，第三列为

  related

  ，当所处理表格为TableB时，第三列为

  likes

示例逻辑为：

查看

表格B

（丈夫）格雷格和妻子（玛丽）的第一行，它从表格a中查看格雷格位于第1行（id 1），玛丽位于第2行（id 2），并创建一个新表格，第一行为1 | 2

---

是否有一个查询可以执行一些连接，或者可以执行一些操作，而不必通过编程方式遍历TABLEB的所有行，然后遍历TABLEC的所有行以生成所需的表？

您需要使用

TABLEB将表
连接到
tablea
两次：


一个用于丈夫
对象
，另一个用于
一个用于妻子

对象

这样您就可以在同一行中获得丈夫和妻子的两个ID

与

table C

与

table A

相同。然后使用

UNION

（隐式distinct）或

UNION ALL

合并两个结果集

比如：

SELECT
  (@rownum := @rownum + 1) AS id,
  sub.*
FROM
(
  SELECT 
    ah.id     AS a,
    aw.id     AS b,
    'related' AS link
  FROM tableb       AS b
  INNER JOIN Tablea AS ah ON ah.object = b.husband AND ah.type = 'person'
  INNER JOIN Tablea AS aw ON aw.object = b.wife    AND aw.type = 'person'
  UNION ALL
  SELECT
    a.id  AS a,
    a2.id AS b,
    'hobby'
  FROM tablec       AS c
  INNER JOIN tablea AS a  ON a.object  = c.female 
  INNER JOIN tablea AS a2 ON a2.object = c.hobby AND a2.type = 'hobby'
) AS Sub, (SELECT @rownum := 0) AS t;

这将为您提供：

| ID | A | B |    LINK |
------------------------
|  1 | 1 | 2 | related |
|  2 | 3 | 4 | related |
|  3 | 6 | 4 | related |
|  4 | 2 | 7 |   hobby |
|  5 | 4 | 8 |   hobby |

注意：

• 此查询将只提供5行，其中您要查找的预期结果集为6。它缺少与

  4 | 1 | 4 |相关的行

  ，因为在

  表B

  中没有针对那些

  greg

  （id 1）和

  keyl

  （id 4）的条目。正如你在问题中解释的那样

• 新列

  id

  是从结果集生成的自动增量id，它不是从表中选择的

---

如果需要从此选择创建全新的表，请使用以下语法：

CREATE TABLE Tabled
AS
SELECT ...
... -- the same previous select query

您将有一个新的表

table

，它的结构与此

SELECT

相同