在MySQL中结合多个查询结果(按列)

内容导读

互联网集市收集整理的这篇技术教程文章主要介绍了在MySQL中结合多个查询结果(按列)，小编现在分享给大家，供广大互联网技能从业者学习和参考。文章包含4382字，纯文字阅读大概需要7分钟。

内容图文

我有4个不同的查询,每个查询返回单独的结果集.
我需要将查询结果与使用单个查询相结合.

我的示例查询是：

1. select cls.* from (calls as cls inner join calls_users as clsusr on cls.id=clsusr.call_id) inner join users as usr on usr.id=cls.assigned_user_id where cls.assigned_user_id='seed_max_id'

2. select mtn.* from (meetings as mtn inner join meetings_users as mtnusr on mtn.id=mtnusr.meeting_id) inner join users as usr on usr.id=mtn.assigned_user_id where mtn.assigned_user_id='seed_max_id'

3. select tsk.* from tasks as tsk inner join users as usr on usr.id=tsk.assigned_user_id where tsk.assigned_user_id='seed_max_id'

4. select nts.* from (notes as nts inner join accounts as acnts on acnts.id=nts.parent_id) inner join users as usr on usr.id=acnts.assigned_user_id where acnts.assigned_user_id='seed_max_id'

我尝试了以下方式,但它没有用

Combine: SELECT tbl1.*, tbl2.* 
from (select cls.* from (calls as cls inner join calls_users as clsusr on cls.id=clsusr.call_id) inner join users as usr on usr.id=cls.assigned_user_id where cls.assigned_user_id='seed_max_id') as tbl1 
left  outer join
(select mtn.* from (meetings as mtn inner join meetings_users as mtnusr on mtn.id=mtnusr.meeting_id) inner join users as usr on usr.id=mtn.assigned_user_id where mtn.assigned_user_id='seed_max_id') as tbl2
using(assigned_user_id)

我也尝试了右外连接和其他内连接
我真的被困了,如果有人知道解决方案那么请帮忙.
我需要像How can I join two tables with different number of rows in MySQL?这样的类似结果.

数据样本：

从查询1：

+-------------------------------------------+------------------+-
| Call Name                                 | Call Description |
+-------------------------------------------+------------------+-
| Discuss Review Process                    | NULL             |
| Get More information on the proposed deal | NULL             |
| Left a message                            | NULL             |
| Discuss Review Process                    | NULL             |
+-------------------------------------------+------------------+

从查询2：

+-----------------------+-----------------------------------------------------------
| Meeting Name          | Meeting Description
+-----------------------+-----------------------------------------------------------
| Review needs          | Meeting to discuss project plan and hash out the details o
| Initial discussion    | Meeting to discuss project plan and hash out the details o
| Demo                  | Meeting to discuss project plan and hash out the details o
| Discuss pricing       | Meeting to discuss project plan and hash out the details o
| Review needs          | Meeting to discuss project plan and hash out the details o
+-----------------------+-----------------------------------------------------------

我需要组合如下列：

+-------------------------------------------+------------------+-------------------+-------------------+
| Call Name                                 | Call Description |Meeting Name       |Meeting Description|
+-------------------------------------------+------------------+-------------------+-------------------+
| Discuss Review Process                    | NULL             |Review needs       |Meeting to discuss |
| Get More information on the proposed deal | NULL             |Initial discussion |Meeting to discuss |
| Left a message                            | NULL             |Demo               |Meeting to discuss |
| NULL                                   | NULL             |Discuss pricing    |Meeting to discuss |
| NULL                                      | NULL             |Review needs       |Meeting to discuss |
+-------------------------------------------+------------------+-------------------+-------------------+

解决方法:

您可以做的最好的是UNION或UNION ALL,但这需要它们具有相同的类型和列数.例如：

SELECT 'Customer' AS type, id, name FROM customer
UNION ALL
SELECT 'Supplier', id, name FROM supplier
UNION ALL
SELECT 'Employee', id, full_name FROM employee

列名称不必匹配.第一部分的别名将用于其余部分.

我还要补充一点,而不是：

select cls.* from (calls as cls inner join calls_users as clsusr on cls.id=clsusr.call_id) inner join users as usr on usr.id=cls.assigned_user_id where cls.assigned_user_id='seed_max_id'

你应该删除不必要的子查询,只需：

SELECT c.*
FROM calls c
JOIN calls_users cu ONc.id = cu.call_id
WHERE c.assigned_user_id = 'seed_max_id'

不需要额外的复杂性,上面的内容显然更具可读性.

内容总结

以上是互联网集市为您收集整理的在MySQL中结合多个查询结果(按列)全部内容，希望文章能够帮你解决在MySQL中结合多个查询结果(按列)所遇到的程序开发问题。 如果觉得互联网集市技术教程内容还不错，欢迎将互联网集市网站推荐给程序员好友。

内容备注

版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 gblab@vip.qq.com 举报，一经查实，本站将立刻删除。

内容手机端