在MySql中查询语法错误

Question

这是我的查询，它在MySql中给出了SQL手动语法错误。

select 
count(case when v.created_at = vv.minva then user_id) as num_new_users
from bills v 
join (select user_id, min(created_at) as minva from bills t group by user_id ) vv 
on v.user_id = vv.user_id 

有人可以帮我解决这个问题吗？

Answer 1

您忘记在CASE声明中使用end。

select 
count(case when v.created_at = vv.minva then user_id end) as num_new_users
from bills v 
join (select user_id, min(created_at) as minva from bills t group by user_id ) vv 
on v.user_id = vv.user_id 

Answer 2

case statement应以end

结束

select 
count(case when v.created_at = vv.minva then user_id end ) as num_new_users
from bills v 
join (select user_id, min(created_at) as minva from bills t group by user_id ) vv 
on v.user_id = vv.user_id