Question

我有多个表格如下：

表1：产品

+-----+----------+--------+---------------------+
| id  |   biz_id | name   |    message          |
+-----+----------+--------+---------------------+
| 1   |   1      | test1  | One tow three       |
| 2   |   1      | test1  | One tow three       |
| 3   |   1      | test1  | One tow three       |
| 4   |   2      | test2  | hello world         |
| 5   |   2      | test2  | hello world         |   
+-----+----------+--------+---------------------+

表2：图像

+-----+----------+--------------+-------------------+
| id  |   biz_id | product_id   |    path           |
+-----+----------+--------------+-------------------+
| 1   |   1      | 1            | img/qwert1.jpg    |
| 2   |   1      | 2            | img/qwert2.jpg    |
| 3   |   1      | 3            | img/qwert3.jpg    |
| 4   |   2      | 4            | img/qwery4.jpg    |
| 5   |   2      | 5            | img/qwert5.jpg    |   
+-----+----------+--------------+-------------------+

如何在连接多个表时避免在mysql中出现重复？

我的查询是加入两个表，以便我想避免重复的产品（按名称获取Distint产品）并获取与该产品相关的所有图像（例如，产品＆gt;名称 - test1有图像qwert1.jpg，qwert2.jpg， qwert2.jpg）

Answer 1


+--------+----------------+------------+------------+-----------------------------+
|Segment_0|  AcctName     |  Budget   | CURRENT BUDGET EXPENSES OCT               |
+--------+----------------+------------+------------+-----------------------------+
| 500101 | Salaries       | 8898033    | 8898033    |                             |
| 500101 | Salaries       | 5459062    | 5459062    |                             |
| 500101 | Salaries       | 452569.6   | 452569.6   |                             |
| 600401 | Operating Cost | 4676556    | 4676556    |                             |
| 600401 | Operating Cost | 1242621.54 | 1242621.54 |                             |
| 600401 | Operating Cost | 882554.4   | 882554.4   |                             |
| 600401 | Operating Cost | 595670.4   | 595670.4   |                             |
+--------+----------------+------------+------------+-----------------------------+

请注意，这不是标准SQL，但大多数DBMS都提供此功能（尽管关键字可能略有不同）。

Answer 2

简单连接应该做所有事情

select p.name as Name, i.message as IMG from Images 
left join Product p
on i.biz_id=p.biz_id
group by p.name;

Answer 3

将left join与GROUP_CONCAT或group by

一起使用

select p.name name,GROUP_CONCAT(i.path) img 
from Images i left join Product p
on i.biz_id=p.biz_id
group by i.product_id

mysql查询以避免重复结果

3 个答案: