总和（）由组SQL

Question

我有下同value和id例如在一排数据：

表名：测试

id | amount 
1 | 100 
1 | 100 
1 | 100 
2 | 150 
2 | 150 
2 | 150 
3 | 200 
3 | 200 
3 | 200 
4 | 250 
4 | 250 
4 | 250 

我要总结在每个id只有一行使用下文sql不工作它总结所有行。

"select *, sum(amount) as total from test group by id"; 

我的问题是，可能sum()只有一个row每个id？

想要的输出？（编辑）

id | amount 
1 | 100 
2 | 150 
3 | 200 
4 | 250 

total : 700 

Answer 1

我的问题是，可能要总结（）只有一排每个ID？

我把它解释为你想要的一个值，每个组都有一行。一种方法是聚集的两个层次：

select sum(amount) 
from (select id, max(amount) as amount 
     from test 
     group by id 
    ) t; 

Answer 2

看起来你需要这个

select *,sum(amount) from (select distinct * from test) as t group by id 

Answer 3

尝试：

select id, sum(amount)/count(*) as total 
from test 
group by id 

结果：

| id | total | 
|----|-------| 
| 1 | 100 | 
| 2 | 150 | 
| 3 | 200 | 
| 4 | 250 | 

Answer 4

尝试这种使用subquery-

select sum(amount) from (select distinct id,amount from company7) as tempTable 

Answer 5

试试这个

create table #test 
(id int, amount int) 

insert into #test values (1,100),(1,100),(1,100),(2,150),(2,150),(3,200),(3,250) 

;with cte 
as 
(
select sum(distinct amount) as damount,id 
from #test 
group by id 
) 

select sum(damount) as total from cte 

对于其他DBMS于SQL Server

select sum(damount) as total from (select sum(distinct amount) as damount,id 
from test 
group by id) as it