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?
A1,
COUNT(DISTINCT A2) AS [A2CNT]
FROM
A
WHERE
A3!=0
GROUP BY
A1
count(case when a3!=0 then a2 end) as a2
from A
group by a1
count(case when a3!=0 then a2 end) as a2
from A
group by a1
from A
group by a1
from A
group by a1
select a1 ,a2行=COUNT(a2) from @A where a3<>0 group by a1
select a1 ,a2行=COUNT(a2) from @A where a3<>0 group by a1
insert into @table
select 'a','b',1,'d' union all
select 'j','h',0,'d' union all
select 'u','j',9,'j'select a1,a2=sum(case when a3<>0 then 1 else 0 end)
from @table group by a1
/*
a1 a2
---- -----------
a 1
j 0
u 1
*/
麦蒂慢了..
select a1,count(*) from A where a3<>0 group by a1
select a1,sum(case when a3<>0 then 1 else 0 end) as a2
from A
group by a1