Mysql从所有表中选择两列

Question

此处之间没有相关表

表1:

id | title   | amount | 
-----------------------
1 | Task1   | 30     | 
2 | Task2   | 20     | 
3 | Task2   | 40     | 
4 | Task2   | 10     | 
5 | Task2   | 30     | 

表2:

id | name   | total | 
---------------------
7  | name1  | 30    | 
8  | name2  | 20    | 
9  | name3  | 40    | 
10 | name4  | 10    | 
11 | name5  | 30    | 

表3:

id | name   | total_count | 
---------------------------
20 | name1  | 10          | 
21 | name2  | 22          | 
22 | name3  | 33          | 
23 | name4  | 23          | 
24 | name5  | 42          |
25 | name6  | 90          |
26 | name7  | 85          |

从每两列的表格中选择，请帮忙，对不起我的英语不好，任何人帮忙，我需要下面的结果：

结果：

t1_title | t1_amount | t2_name | t2_total | t3_name | t3_total |
----------------------------------------------------------------
Task1   | 30        | name1   | 30       | name1   | 10       |
Task2   | 20        | name2   | 20       | name2   | 22       |
Task3   | 40        | name3   | 40       | name3   | 33       |
Task4   | 10        | name4   | 10       | name4   | 23       |
Task5   | 30        | name5   | 30       | name5   | 42       |
| 0         |         | 0        | name6   | 90       |
| 0         |         | 0        | name7   | 87       |

这里没有表之间的相关(关系(。

谢谢！！！

Answer 1

看起来您想要在三个表之间等效的FULL OUTER JOIN，我认为这需要使用三个查询的UNION来实现，例如：

select t1.title, t1.amount, t2.name, t2.total, t3.name, t3.total_count
from t1 left join t2 on t1.id = t2.id left join t3 on t1.id = t3.id
union 
select t1.title, t1.amount, t2.name, t2.total, t3.name, t3.total_count
from t2 left join t1 on t2.id = t1.id left join t3 on t2.id = t3.id
union
select t1.title, t1.amount, t2.name, t2.total, t3.name, t3.total_count
from t3 left join t1 on t3.id = t1.id left join t2 on t3.id = t2.id