Question

我们有3张桌子

表格票据

id | email
---+-----------------
1  | test@gmail.com
2  | test1@gmail.com

表客户

email           | location
----------------+----------
test@gmail.com  | Area1
test!@gmail.com | Area2

表区

location | zone
---------+--------
Area1    | South
Area2    | North

我正在尝试将查询输出为

Count(ticket.id) | Zone
-----------------+-----------
 1               | South
 1               | North

请给我一个很好的建议。提前谢谢！

Answer 1

这是一个简单的join group by

select count(ticket.id), Zone 
from ticket 
join customer on ticket.email=customer.email 
join zone on customer.location=zone.location
group by zone