Question

我有两个行政区划表，如下所示。我试图获得每个教区的市政名称。

市

id       | district_id | name     |
---------|-------------|----------|
01       | 01          | Abc      |
01       | 02          | Cba      |
01       | 03          | Random   |
...

教区

id  | municipality_id | district_id | name |
----|-----------------|-------------|------|
03  | 01              | 01          | Abc  |
09  | 01              | 02          | Zxe  |
12  | 01              | 01          | Tfg  |
19  | 01              | 03          | Qwe  |

查询我尝试没有成功：

SELECT municipalities.Name FROM municipalities
JOIN parishes AS P 
  ON municipalities.id = P.municipality_id
  AND municipalities.district_id = P.district_id;

名字不匹配。如何更改查询以获得每个教区的市政名称？理想情况下，结果将是这样的：

id | municipality_name | parish_name
03 | Abc               | Abc
09 | Cba               | Zxe
...

注意：市政当局的id列没有主键约束。

Answer 1

只需在SELECT之后添加所需的其他列，按照您希望它们返回的顺序，以逗号分隔列出所需的列：

SELECT P.id, municipalities.name, P.name
  FROM municipalities
  JOIN parishes as P
  ...

Answer 2

尝试

SELECT p.id, m.name AS municipality_name, p.name AS parish_name
FROM municipalities m 
  JOIN parishes p ON m.id = p.municipality_id AND m.district_id = p.district_id

Answer 3

只需添加表parishes

中的数据字段即可

SELECT p.id, municipalities.Name, p.name
FROM municipalities
JOIN parishes AS P 
  ON municipalities.id = P.municipality_id
  AND municipalities.district_id = P.district_id;

SQL加入同一个表

3 个答案: