Question

如何从多个表中获取应该最小化和分组的值

像：我有三张桌子

          Table1                              Table3        
|   ID  |   GPN |   PKGID   |           |   GPN |   Amt |
|   1   |   A   |   PKG01   |           |   A   |   10  |
|   2   |   B   |   PKG02   |           |   A   |   15  |
|   3   |   C   |   PKG03   |           |   A   |   20  |
|   4   |   D   |   PKG04   |           |   A   |   25  |
                                        |   A   |   65  |
                                        |   A   |   30  |
-----------------------------           |   B   |   17  |
                                        |   D   |   90  |
                                        |   B   |   20  |
         Table2                         |   B   |   40  |
|   GPN |   Date        |               |   D   |   60  |
|   A   |   2016-09-10  |               |   B   |   80  |
|   A   |   2016-09-18  |               |   B   |   100 |
|   B   |   2016-09-10  |               |   C   |   3   |
|   B   |   2016-09-11  |               |   C   |   6   |
|   B   |   2016-09-12  |               |   C   |   9   |
|   C   |   2016-10-12  |               |   C   |   12  |
|   C   |   2016-10-13  |               |   C   |   15  |
|   C   |   2016-10-14  |               |   D   |   7   |
|   D   |   2016-09-10  |               |   D   |   10  |
|   D   |   2016-10-13  |               |   D   |   13  |

我必须从表中的三个中获取值，所以我该怎么做。

例如

日期= 2016-09-10

我必须得到代表的价值所以结果应该包含所有组的最小值。

结果

|   ID  |   PKGID   |   GPN |       Amt |   Date        |
|   1   |   PKG01   |   A   |       10  |   2016-09-10  |
|   2   |   PKG02   |   B   |       17  |   2016-09-10  |
|   4   |   PKG04   |   D   |       7   |   2016-09-10  |

Answer 1

应该是这个

select table.id, table1.PKGID, table1.GPN, min(table3.Amt), table2.`date`
from table1 
inner join table3 on table1.GPN= table3.GPN
inner join table2 on table1.GPN= table2.GPN
where date(table2.date )  = str_to_date('2016-09-10', '%Y-%m-%d') 
group by table1.GPN, table.id, table1.PKGID, table2.`date`

Answer 2

你也可以尝试这个

SELECT t1.*, MIN(t3.Amt) as Amt, t2.Date
FROM table1 t1
INNER JOIN table2 t2 on t1.GPN= t2.GPN
INNER JOIN table3 t3 on t1.GPN= t3.GPN
WHERE t2.Date  = '2016-09-10' 
GROUP BY t1.GPN

Answer 3

你可以尝试这样的事情。首先通过分组获取MIN(Amt)，然后执行JOIN

select t1.*,
xxx.Amt,
t2.`Date`
from table1 t1 join table2 t2 on t1.GPN = t2.GPN
join (select GPN, min(Amt) as Amt from table3 group by GPN) xxx
on t1.GPN = xxx.GPN;

如何从多个表中获取值，但值应为min和group wise

3 个答案: