不管用: 表名: skaway 字段: id(主键),Power(段电情况,0为段电,1为正常),powerTime(时间,不重复)select distinct power 供电状态,powerTime as 时间 from skaway有没有那位高手能解决,谢谢了!
请问楼主:下面的是没有重复的吗? 0 1 0 1 ???????????????? 删除重复记录的语句如下:(假设0,1,0,1字段名为fieldname,每条记录的标识字段名为id)delete from tablename where id no in( select id from tablename tn where fieldname in ( select fidldname from tablename where tn.id=id))
select id,[power] 供电状态,powerTime 时间,0 flag into #临时表 from skaway declare @a int,@b int select @a=0,@b=0 update #临时表 set @a=case when @b=供电状态 then @a else @a+1 end,@b=供电状态,flag=@a select min(供电状态),min(时间) from #临时表 group by flagdrop table #临时表
编写一个存储过程来查询,并执行delete操作
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...)
表名: skaway
字段: id(主键),Power(段电情况,0为段电,1为正常),powerTime(时间,不重复)select distinct power 供电状态,powerTime as 时间 from skaway有没有那位高手能解决,谢谢了!
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删除重复记录的语句如下:(假设0,1,0,1字段名为fieldname,每条记录的标识字段名为id)delete from tablename where id no in(
select id from tablename tn where fieldname in (
select fidldname from tablename where tn.id=id))
declare @a int,@b int
select @a=0,@b=0
update #临时表 set @a=case when @b=供电状态 then @a else @a+1 end,@b=供电状态,flag=@a
select min(供电状态),min(时间) from #临时表 group by flagdrop table #临时表
)
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...)