mysql - 如何根据表中选择的百分比将行值分配给不同的值

Question

很抱歉提前提出了含糊的问题。

我有下表:

State   Sales
AL  1000
AK  2000
MI  4000
MA  3000
PA  1500
WY  3000
NY  2000
VM  1000

现在每个州属于一个或多个区域:

Regions 
AB: AL, 50%AK
CD: 50%Ak, MI
EF: MA, PA, 25%WY
GH: 75%WY, NY, VM

我想要下表:

State Region Sales
AL   AB   1000
AK   AB   1000
AK   CD   1000
MI   CD   4000
MA   EF   3000
PA   EF   1500
WY   EF   750
WY   GH   2250
NY   GH   2000
VM   GH   1000 

我有一些 SQL 经验，但我不知道如何继续。有什么指点吗？

Answer 1

删除了我之前的答案，您的架构是正确的，但是您应该在区域表上添加数据(或将其重命名为另一个表名称，当该表被命名为区域时会很困惑)，如下所示:

region_code state_code  percentage
AB           AL           100
AB           AK           50
CD           Ak           50
CD           MI           100
EF           MA           100
EF           PA           100
EF           WY           25
GH           WY           75
GH           NY           100
GH           VM           100

那么您的查询将类似于:

SELECT State.code, Region.code, ((Region.percentage * State.sales) / 100) as Sales 
FROM State
INNER JOIN Region
ON State.code = Region.state_code

NOTE: this answer is made to have a small changes on your schema. This answer serve as an example or to give you an idea. I suggest you analyze more on how your database schema should be made. Normalizing database and Proper naming of tables should be done if needed