sql语句删除重复的记录的方法.doc

sql语句删除重复的记录的方法例如:idnamevalue1app2app3biii4bpp5bpp6cpp7cpp8ciiiid是主键要求得到这样的结果idnamevalue1app3biii4bpp6cpp8ciii方法1deleteYourTablewhere[id]notin(selectmax([id])fromYourTablegroupby(name+value))方法2deleteafrom表aleftjoin(select(id)from表groupbyname,value)=、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*frompeoplewherepeopleIdin(selectpeopleIdfrompeoplegroupbypeopleIdhavingcount(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deletefrompeoplewherepeopleIdin(selectpeopleIdfrompeoplegroupbypeopleIdhavingcount(peopleId)>1)androwidnotin(selectmin(rowid)frompeoplegroupbypeopleIdhavingcount(peopleId)>1)3、查找表中多余的重复记录(多个字段)select*fromvitaeawhere(,)in(selectpeopleId,seqfromvitaegroupbypeopleId,seqhavingcount(*)>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deletefromvitaeawhere(,)in(selectpeopleId,seqfromvitaegroupbypeopleId,seqhavingcount(*)>1)androwidnotin(selectmin(rowid)fromvitaegroupbypeopleId,seqhavingcount(*)>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*fromvitaeawhere(,)in(selectpeopleId,seqfromvitaegroupbypeopleId,seqhavingcount(*)>1)androwidnotin(selectmin(rowid)fromvitaegroupbypeopleId,seqhavingcount(*)>1)(二)比方说在A表中存在一个字段“name”,而且不同记录之间的“name”值有可能会相同,现在就是需要查询出在该表中的各记录之间,“name”值存在重复的项;SelectName,Count(*)FromAGroupByNameHavingCount(*)>1如果还查性别也相同大则如下:SelectName,sex,Count(*)FromAGroupByNa