select distince * into #tmp from tablename
truncate table tablename
select * into tablename from #tmp
truncate table tablename
select * into tablename from #tmp
解决方案 »
- 一个简单的SQL语句问题请高手帮忙解决一下,在线等回答
- 我用Macromedia Dreamweaver做的ASP,里面涉及建立的记录集,上面三附图有关情况麻烦解决!
- 查询,求平均值问题。怎么写能最简
- 数据导入问题,向各位大侠请教!! 急急
- 选择性备份问题
- [DENETLTB][ConnectionOpen(Connect()).]SQL Server不存在或拒绝访问???
- 請教distinct select 問題
- SQLServer2000中企业管理器问题“未找到提供者,可能未被正确安装”???
- SQL Server 2000 表中数据删除了怎么还原阿
- 如何修改已有大量数据的表的结构
- 我希望大家能给我关于两个虚表用法的帮助!
- 怎样在Delphi中调用DTS,你会吗?高手请进
truncate table table_name
insert into table_name select * from T
drop table T
蚂蚁的:去除重复值
如果有ID字段,就是具有唯一性的字段delect table where id not in ( select max(id) from table group by col1,col2,col3...
)
group by 子句后跟的字段就是你用来判断重复的条件,如只有col1,那么只要col1字段内容相同即表示记录相同。2,如果是判断所有字段也可以这样
select * into #aa from table group by id1,id2,....
delete table
insert into table
select * from #aa3,没有ID的情况select identity(int,1,1) as id,* into #temp from tabel
delect # where id not in (
select max(id) from # group by col1,col2,col3...)
delect table
inset into table(...)
select ..... from #temp
col1+','+col2+','...col5 联合主键
select * from table where col1+','+col2+','...col5 in ( select max(col1+','+col2+','...col5) from table
where having count(*)>1
group by col1,col2,col3,col4
)
group by 子句后跟的字段就是你用来判断重复的条件,如只有col1,那么只要col1字段内容相同即表示记录相同。2,
select identity(int,1,1) as id,* into #temp from tabel
select * from #temp where id in (
select max(id) from #emp where having count(*)>1 group by col1,col2,col3...)
truncate table table_name
insert into table_name select * from Table
drop table Table