在几千条记录里,存在着些相同的记录,如何能用SQL语句,删除掉重复的呢
1、查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断 
ｓｅｌｅｃｔ * from people 
where peopleId in (ｓｅｌｅｃｔ peopleId from people group by peopleId having count(peopleId) > 1) 

2、删除表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断，只留有rowid最小的记录 
ｄｅｌｅｔｅ from people 
where   peopleName in (ｓｅｌｅｃｔ peopleName    from people group by peopleName      having count(peopleName) > 1) 
ａｎｄ   peopleId not in (ｓｅｌｅｃｔ min(peopleId) from people group by peopleName     having count(peopleName)>1) 

3、查找表中多余的重复记录（多个字段） 
ｓｅｌｅｃｔ * from vitae a 
where (a.peopleId,a.seq) in (ｓｅｌｅｃｔ peopleId,seq from vitae group by peopleId,seq having count(*) > 1) 

4、删除表中多余的重复记录（多个字段），只留有rowid最小的记录 
ｄｅｌｅｔｅ from vitae a 
where (a.peopleId,a.seq) in (ｓｅｌｅｃｔ peopleId,seq from vitae group by peopleId,seq having count(*) > 1) 
ａｎｄ rowid not in (ｓｅｌｅｃｔ min(rowid) from vitae group by peopleId,seq having count(*)>1) 

5、查找表中多余的重复记录（多个字段），不包含rowid最小的记录 
ｓｅｌｅｃｔ * from vitae a 
where (a.peopleId,a.seq) in (ｓｅｌｅｃｔ peopleId,seq from vitae group by peopleId,seq having count(*) > 1) 
ａｎｄ rowid not in (ｓｅｌｅｃｔ min(rowid) from vitae group by peopleId,seq having count(*)>1)   

6.消除一个字段的左边的第一位：

ｕｐｄａｔｅ tableName set [Title]=Right([Title],(len([Title])-1)) where Title like ’村%’

7.消除一个字段的右边的第一位：

ｕｐｄａｔｅ tableName set [Title]=left([Title],(len([Title])-1)) where Title like ’%村’

8.假删除表中多余的重复记录（多个字段），不包含rowid最小的记录 
ｕｐｄａｔｅ vitae set ispass=-1
where peopleId in (ｓｅｌｅｃｔ peopleId from vitae group by peopleID