急求sql语句（过滤重复数据）
字段1 字段2 字段3
现在字段1 和字段2 有重复数据 但是 字段3 缺不全是重复数据
先前我只需要查询字段1和字段2的数据 并且过滤掉重复数据是这样
select distinct 字段1,字段2 from tableName
但是现在需要增加字段3 这样该怎么写
[解决办法]
try this,
select 字段1,字段2,字段3 from
(select 字段1,字段2,字段3,
row_number() over(partition by 字段1,字段2 order by 字段3) 'rn'
from [表名]) t
where t.rn=1
select *
from [huang] a
WHERE EXISTS (SELECT 1 FROM (SELECT [字段1],[字段2],MAX([字段3])[字段3] FROM huang GROUP BY [字段1],[字段2])b
WHERE a.[字段1]=b.字段1 AND a.[字段2]=b.字段2 AND a.[字段3]=b.[字段3])
select 字段1,字段2,min(字段3) as 字段3 from group by 字段1,字段2
----------------------------------------------------------------
-- Author :DBA_Huangzj(發糞塗牆)
-- Date :2013-11-05 14:43:40
-- Version:
-- Microsoft SQL Server 2012 (SP1) - 11.0.3128.0 (X64)
--Dec 28 2012 20:23:12
--Copyright (c) Microsoft Corporation
--Enterprise Edition (64-bit) on Windows NT 6.2 <X64> (Build 9200: )
--
----------------------------------------------------------------
--> 测试数据：[huang]
if object_id('[huang]') is not null drop table [huang]
go
create table [huang]([字段1] int,[字段2] int,[字段3] int)
insert [huang]
select 1,1,2 union all
select 1,1,3 union all
select 2,2,3 union ALL
select 2,2,4
--------------开始查询--------------------------
select *
from [huang] a
WHERE EXISTS (SELECT 1 FROM (SELECT [字段1],[字段2],MIN([字段3])[字段3] FROM huang GROUP BY [字段1],[字段2])b
WHERE a.[字段1]=b.字段1 AND a.[字段2]=b.字段2 AND a.[字段3]=b.[字段3])
----------------结果----------------------------
/*
字段1 字段2 字段3
----------- ----------- -----------
1 1 2
2 2 3
*/
select 字段1,字段2,字段3 from
(select 字段1,字段2,字段3,
row_number() over(partition by 字段1,字段2 order by 字段3) 'rn'
from [表名]) t
where t.rn=1
