两个SQL COUNT（）查询？

一种方法是将表与自身连接：

select   count(*) as TotalCount,   count(s.id) as QualifiedCountfrom   MyTable aleft join   MyTable s on s.id = a.id and {some conditions}

另一种方法是使用子查询：

select   (select count(*) from Mytable) as TotalCount,   (select count(*) from Mytable where {some conditions}) as QualifiedCount

或者，您可以将条件放在一个案例中：

select   count(*) as TotalCount,   sum(case when {some conditions} then 1 else 0 end) as QualifiedCountfrom   MyTable