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