无法准备语句（1 次滥用聚合函数 COUNT()） - 第 2 部分

Question

我正在尝试运行以下查询：

select U1.userEmail, U1.firstname + ' ' + U1.surName as fullname 
from tblUser as U1 inner join tblDriver as D on U1.userEmail= D.userEmail
inner join tblGetAsk as GA  on GA.userEmail = D.userEmail
where not exists (select 1 from tblRideRating as R where R.userEmail = U1.userEmail)
and count(GA.userEmail) >= 3

但我收到以下错误：

错误 1：无法准备语句（1 滥用聚合函数 计数（））

我真正想做的是：只选择同时也是司机并且在tblRideRating中有0条记录，并且在tblGetAsk中至少有3条记录的用户。

Answer 1

您可以使用聚合。
按用户分组并使用HAVING 子句：

select U1.userEmail, U1.firstname + ' ' + U1.surName as fullname 
from tblUser as U1 
inner join tblDriver as D on D.userEmail= U1.userEmail
inner join tblGetAsk as GA on GA.userEmail = U1.userEmail
where not exists (select 1 from tblRideRating as R where R.userEmail = U1.userEmail)
group by U1.userEmail, U1.firstname + ' ' + U1.surName
having count(GA.userEmail) >= 3

如果您在tblGetAsk 中的每个用户都有重复的电子邮件，也许您应该更改为：

having count(distinct GA.userEmail) >= 3

你也可以在tblGetAsk聚合然后加入：

select U1.userEmail, U1.firstname + ' ' + U1.surName as fullname 
from tblUser as U1 
inner join tblDriver as D on D.userEmail= U1.userEmail
inner join (
  select userEmail
  from tblGetAsk
  group by userEmail
  having count(*) >= 3 
) as GA on GA.userEmail = U1.userEmail
where not exists (select 1 from tblRideRating as R where R.userEmail = U1.userEmail)