declare @trade table(id int,name varchar(10))
insert @trade select 1,'aaa'
union all select 2,'bbb'
union all select 3,'ccc'
--------------------------------------------
declare @detail table(id int,trade_id int,money int)
insert @detail select 1,1,30
union all select 2,1,20
union all select 3,2,20
union all select 3,2,20
--------------------------------------------
--SQL语句
select A.id,A.name,isnull(B.money,0) as money
from @trade A left join
(
select trade_id,sum(money) as money
from @detail
group by trade_id) B
on A.id=B.trade_id
where A.id=1 --条件