关于左连接取值的问题？谢谢
drop table input
drop table inputSub
drop table output
drop table outputSub

create table input
(
  id int, --编号
  name nvarchar(20), --名称
  inNum int --接收数
)

create table inputSub
(
  id int,
  printed char(1)
)

create table output
(
  id int,
  name nvarchar(20),
  outNum int --发送数
)

create table outputSub
(
  id int,
  printed char(1)
)
---表说明---------------
--input ：接收记录
--inputSub ：接收确认,形成实际接收
--output ：发送记录
--outpubSub ：发送确认,形成实际发送

---测试数据----------
insert into input (id,name,inNum) values (1,'AA',20)
insert into input (id,name,inNum) values (2,'BB',10)
insert into input (id,name,inNum) values (3,'CC',30)
insert into input (id,name,inNum) values (4,'AA',40)
insert into input (id,name,inNum) values (5,'DD',15)
insert into input (id,name,inNum) values (6,'EE',20)
insert into input (id,name,inNum) values (7,'BB',50)
insert into input (id,name,inNum) values (8,'AA',20)
insert into input (id,name,inNum) values (9,'FF',35)

insert into inputSub (id,printed) values (1,'Y')
insert into inputSub (id,printed) values (3,'Y')
insert into inputSub (id,printed) values (5,'Y')
insert into inputSub (id,printed) values (7,'Y')
insert into inputSub (id,printed) values (9,'Y')


insert into output (id,name, outnum) values (1,'BB',5)
insert into output (id,name, outnum) values (2,'BB',10)
insert into output (id,name, outnum) values (3,'CC',10)
insert into output (id,name, outnum) values (4,'CC',25)
insert into output (id,name, outnum) values (5,'EE',10)
insert into output (id,name, outnum) values (6,'DD',5)

insert into outputSub (id,printed) values (2,'Y')
insert into outputSub (id,printed) values (4,'Y')
insert into outputSub (id,printed) values (6,'Y')


-------------以上为脚本-------------------------------------

--查询要求：
--同一名称的实际接收数,即: 实际接收的 - 实际发送的

-- 第一结果集
select input.name, sum(inNum) 
from input
inner join inputSub on input.id= inputSub.id and inputSub.printed = 'Y'
group by input.name

AA 20
BB 50
CC 30
DD 15
FF 35


--第二结果集
select output.name,sum(outNum)
from output
inner join outputSub on output.id= outputSub.id and outputSub.printed = 'Y'
group by output.name

BB 10
CC 25
DD 5


要求第一结果集去 左连接 第二结果集 条件是 input.name = output.name

AA 20
BB 40
CC 5
DD 10
FF 35

我的语句：得不到结果呀
select input.name, sum(inNum) - sum(outNum)
from input
inner join inputSub on input.id= inputSub.id and inputSub.printed = 'Y'
left join output on input.name = output.name 
left join outputSub on output.id = outputSub.id and outputSub.printed = 'Y'
group by input.name

------解决方案--------------------

SQL code

create table input 
( 
  id  int,   --编号 
  name nvarchar(20),  --名称 
  inNum int  --接收数 
) 

create table inputSub 
( 
  id  int, 
  printed char(1) 
) 

create table output 
( 
  id  int, 
  name nvarchar(20), 
  outNum int  --发送数 
) 

create table outputSub 
( 
  id  int, 
  printed char(1) 
) 


insert into input (id,name,inNum) values (1, 'AA ',20) 
insert into input (id,name,inNum) values (2, 'BB ',10) 
insert into input (id,name,inNum) values (3, 'CC ',30) 
insert into input (id,name,inNum) values (4, 'AA ',40) 
insert into input (id,name,inNum) values (5, 'DD ',15) 
insert into input (id,name,inNum) values (6, 'EE ',20) 
insert into input (id,name,inNum) values (7, 'BB ',50) 
insert into input (id,name,inNum) values (8, 'AA ',20) 
insert into inp