szhswl
          宋針還的個人空間

          1、查找表中多余的重復記錄,重復記錄是根據單個字段(peopleId)來判斷
          select * from people
          where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)

          2、刪除表中多余的重復記錄,重復記錄是根據單個字段(peopleId)來判斷,只留有rowid最小的記錄
          delete from people
          where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
          and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )>1)

          3、查找表中多余的重復記錄(多個字段)
          select * from vitae a
          where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)

          4、刪除表中多余的重復記錄(多個字段),只留有rowid最小的記錄
          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、查找表中多余的重復記錄(多個字段),不包含rowid最小的記錄
          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)


          利用rowid重復記錄的查詢還可以用下面SQL:
          select * from people p1
          where p1.rowid not in (select max(rowid) from people p2 where p2.peopleId = p1.peopleId)

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          說人之短,乃護己之短。夸己之長,乃忌人之長。皆由存心不厚,識量太狹耳。能去此弊,可以進德,可以遠怨。
          http://www.aygfsteel.com/szhswl
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          posted on 2007-12-03 15:48 宋針還 閱讀(724) 評論(0)  編輯  收藏 所屬分類: SQL
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