一个sql的基础查询问题

[tony_198642]

已有两个结果集
A B
1 1
2 1
3 1

A C
1 1
4 1

我想查询出以下结果集

A B C
1 1 1
2 1 0
3 1 0

[百年树人]

select a.*,isnull(b.c,0) as c
from ta a
left join tb b
on a.a=b.a

[--小F--]

select
  a.*,isnull(b.c,0) as c
from
  a left join b
on
  a.a=b.a

[SQL77]

----------------------------------------------------------------
-- Author  :SQL77(只为思齐老)
-- Date    :2010-01-20 13:29:19
-- Version:
--      Microsoft SQL Server  2000 - 8.00.194 (Intel X86) 
--	Aug  6 2000 00:57:48 
--	Copyright (c) 1988-2000 Microsoft Corporation
--	Desktop Engine on Windows NT 5.1 (Build 2600: Service Pack 3)
--
----------------------------------------------------------------
--> 测试数据：#TB
if object_id('tempdb.dbo.#TB') is not null drop table #TB
go 
create table #TB([A] int,[B] int)
insert #TB
select 1,1 union all
select 2,1 union all
select 3,1
--> 测试数据：#TB1
if object_id('tempdb.dbo.#TB1') is not null drop table #TB1
go 
create table #TB1([A] int,[C] int)
insert #TB1
select 1,1 union all
select 4,1
--------------开始查询--------------------------

select A.A,A.B,ISNULL(B.C,0)C  from #TB A LEFT JOIN #TB1 B ON A.A=B.A

----------------结果----------------------------
/* 

（所影响的行数为 3 行）


（所影响的行数为 2 行）

A           B           C           
----------- ----------- ----------- 
1           1           1
2           1           0
3           1           0

（所影响的行数为 3 行）


*/

[-狙击手-]

joy

[ws_hgo]

if object_id('tempdb.dbo.#TB') is not null drop table #TB
go 
create table #TB([A] int,[B] int)
insert #TB
select 1,1 union all
select 2,1 union all
select 3,1
--> 测试数据：#TB1
if object_id('tempdb.dbo.#TB1') is not null drop table #TB1
go 
create table #TB1([A] int,[C] int)
insert #TB1
select 1,1 union all
select 4,1


select A.*,isnull(B.[C],0) C from #TB A left join #TB1 B on A.[A]=B.[A]
A           B           C
----------- ----------- -----------
1           1           1
2           1           0
3           1           0

[Mr_Nice]

...

[h821291419]

楼上的真的忒快啊

[ben_key01]

declare @t TABLE (A VARCHAR(1),B INT)

INSERT INTO @t
SELECT '1',1
UNION ALL
SELECT '2',1
UNION ALL
SELECT '3',1


declare @t1 TABLE (A1 VARCHAR(1),c INT)

INSERT INTO @t1
SELECT '1',1
UNION ALL
SELECT '4',1


SELECT a,b, isnull(c,0) c FROM @t LEFT JOIN @t1 ON a=a1

[cxmcxm]

--设两表名为t1,t2
select t1.a,t1.b,isnull(t2.c,0) as C
from T1 left join T2 on t1.a=t2.a

[jdhlowforever]

[Quote=引用 1 楼 josy 的回复:]
SQL codeselect a.*,isnull(b.c,0)as cfrom ta aleftjoin tb bon a.a=b.a
[/Quote]

select a.*,isnull(b,c,0) as c from ta a left join tb b on a.a=b.a