用SQL语句,删除掉重复项只保留一条

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    peopleWHERE    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

DELETEFROM    peopleWHERE    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 aWHERE    (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

DELETEFROM    vitae aWHERE    (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 aWHERE    (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 tableNameSET [ 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 tableNameSET [ 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 vitaeSET ispass =- 1WHERE    peopleId IN (        SELECT            peopleId        FROM            vitae        GROUP BY            peopleId