提问者:小点点

选择带有计数和内部联接的查询


我面临一些困难,因为我在SQL方面不是很有经验。 我有表格:


 -----------------    -------------------
| membership_info |  |  client_info      |
 -----------------    -------------------
| ID (PK)         |  | client_id (FK)    |
| Name            |  | membership_id (FK)|
| Price           |  | value_paid        |
 -----------------    -------------------

membership_info和client_info具有如下值:


 --------------------------     ----------------------------------------
|  ID  |  Name   |  Price  |   | client_id | membership_id | value_paid |
 --------------------------     ----------------------------------------
|  1   | Daily   |   30    |   |     24    |       2       |     80     |
|  2   | Weekly  |   80    |   |     25    |       2       |     80     |
|  3   | Monthly |  100    |   |     26    |       3       |     100    |
 --------------------------     ----------------------------------------

现在我面临的问题是,我不知道如何查询如下所示的结果:


 -------------------------------------
| Membership Name  | Membership Count |
 -------------------------------------
|     Weekly       |         2        |
|     Monthly      |         1        |
 -------------------------------------

请救命!


共1个答案

匿名用户

select name, count(*)
from client_info c
    inner join membership_info m on c.membership_id = m.id
group by name