请问一个多表查询插入语句_Sql Server

请教一个多表查询插入语句
A表是客户信息表（用户名不重复），字段： userName、UserLl
B表是业务表(各用户都有很多业务)，字段：UserName 、YwMoney

现在想将A表和B表综合插入到C表中

C表字段： UserName UserLl YwMoney(要合计)

请问这个SQL要怎么写呢？请高手指点小弟。

------解决方案--------------------

SQL code

insert c(UserName,UserLl,YwMoney)select a.userName,a.UserLl,isnull(b.YwMoney,0)from aleft join (select UserName,sum(YwMoney) as YwMoney from b group by UserName) bon a.UserName=b.UserName
------解决方案--------------------
探讨
SQL code
insert c(UserName,UserLl,YwMoney)
select a.userName,a.UserLl,isnull(b.YwMoney,0)
from a
left join (select UserName,sum(YwMoney) as YwMoney from b group by UserName) b
on a.UserName=b.Use……

------解决方案--------------------
SQL codeselect t1.userName,t1.UserLl,YwMoney=sum(YwMoney) into C from A t1 inner join B t2 on t1.userNmae=t2.userName group by t1.userName,t1.UserLl
------解决方案--------------------
SQL codeinsert into    cselect   *from   (    select  userName,UserLl,0 as YwMoneyfrom a    union all    select UserName,'',sum(YwMoney) as YwMoney from b group by UserName)t
------解决方案--------------------
探讨
SQL code

insert into 
   c
select
   *
from
   (
    select  userName,UserLl,0 as YwMoneyfrom a
    union all
    select UserName,'',sum(YwMoney) as YwMoney from b group by UserName)t