数据表A 字段 a1,a2,a3,a4 a3是int类型 其他vachar
想把 A表中 按 a1分组,把a3不等于 0的 所有a2的 行数计算出来。。select a1,count(a2) from A group by a1
请问这里怎么做判断 ,count(a2) 计算出 a3不等于0时,所有a2的行数?
想把 A表中 按 a1分组,把a3不等于 0的 所有a2的 行数计算出来。。select a1,count(a2) from A group by a1
请问这里怎么做判断 ,count(a2) 计算出 a3不等于0时,所有a2的行数?
from A
group by a1
declare @table table (a1 varchar(1),a2 varchar(1),a3 int,a4 varchar(1))
insert into @table
select 'a','b',1,'d' union all
select 'j','h',0,'d' union all
select 'u','j',9,'j'select count(a2) from @table where a3<>0
--为什么要放在select中判断?
from A
group by a1
from A
group by a1
from A
group by a1