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  • SQLServer删除重复行

    1.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 #aa 

    3. 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 
    

      

    4. 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。 

    5. 

     
    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...) 

    6. 

     
    select distinct * into #temp from tablename 
    delete tablename 
    go 
    insert tablename select * from #temp Sqlclub 
    go 
    drop table #temp 
    

      

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  • 原文地址:https://www.cnblogs.com/Williamls/p/10760961.html
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