[求sql语句]表中数据有重复，如何删掉重复的部分（重复的数据保留一条）_Sql Server

[求sql语句]表中数据有重复，怎么删掉重复的部分（重复的数据保留一条）
Users中有三个字段：UserName、Sex、Age。若两条记录的三个字段都相同，则为重复。
为了方便大家，我把sql语句写出来，如下所示：

SQL code

create table Users(    [UserName] nvarchar(32) not null,    [Sex] bit not null,    [Age] int not null,);insert into Users values('王杰', 1, 40);insert into Users values('王杰', 1, 40);insert into Users values('王杰', 1, 40);insert into Users values('苏有朋', 1, 40);insert into Users values('苏有朋', 1, 40);insert into Users values('刘德华', 1, 40);insert into Users values('刘德华', 0, 40);

上面的的例子，执行完删除sql之后，最后要只剩下4条数据：
'王杰', 1, 40 （有三条重复的，删掉两条）
'苏有朋', 1, 40 （有两条重复的，删除一条）
'刘德华', 1, 40
'刘德华', 0, 40

谢谢大家！

------解决方案--------------------
建立个unique index,以后就没这麻烦事啦。
------解决方案--------------------

SQL code

---先把符合条件记录放入一个临时表中，select distinct UserName,Sex,Age   into #temp from Users----然后把原表删除掉  delete Users----然后把临时表记录插入insert into Usersselect UserName,Sex,Age   from #temp
------解决方案--------------------
所有列都存在重复的话,需要借用临时表来实现.
SQL codecreate table Users(    [UserName] nvarchar(32) not null,    [Sex] bit not null,    [Age] int not null,);insert into Users values('王杰', 1, 40);insert into Users values('王杰', 1, 40);insert into Users values('王杰', 1, 40);insert into Users values('苏有朋', 1, 40);insert into Users values('苏有朋', 1, 40);insert into Users values('刘德华', 1, 40);insert into Users values('刘德华', 0, 40);goselect distinct * into tmp from userstruncate table usersinsert into users select * from tmpdrop table tmpselect * from users/*UserName                         Sex  Age         -------------------------------- ---- ----------- 刘德华                              0    40刘德华                              1    40苏有朋                              1    40王杰                               1    40（所影响的行数为 4 行）*/drop table users
------解决方案--------------------
select username,sex,age from users group by username,sex,age
------解决方案--------------------

delete from (select run_number()over(order by username,sex,age) as odr  from users)a
where a.odr<>1

------解决方案--------------------
SQL codecreate table Users(    [UserName] nvarchar(32) not null,    [Sex] bit not null,    [Age] int not null,);insert into Users values('王杰', 1, 40);insert into Users values('王杰', 1, 40);insert into Users values('王杰', 1, 40);insert into Users values('苏有朋', 1, 40);insert into Users values('苏有朋', 1, 40);insert into Users values('刘德华', 1, 40);insert into Users values('刘德华', 0, 40);;with _a as(    select row_number()over(partition by username,sex,age order by username) as coou,* from users)select username,sex,age from _a where coou=1
------解决方案--------------------
SQL code-- 查出数据插入新表select [UserName],[sex],[age] from (    select     r=row_number() over (partition by [UserName],[sex],[age] order by newid()),*    from users) a where a.r=1-- 删除旧表，新表.表名 = 旧表.表名
------解决方案--------------------
SQL code--删除重复记录--1),delete from tablename where id not in (select max(id) from tablename group by col1,col2,...)--2),select distinct * into temp from tablenamedelete from tablenameinsert into tablename select * from temp