幾種查找和刪除重復記錄的方法

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幾種查找和刪除重復記錄的方法

1、查找表中多余的重復記錄，重復記錄是根據(jù)單個字段（peopleId）來判斷

1. select * from people
   
2. 
   
3. where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)

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2、刪除表中多余的重復記錄，重復記錄是根據(jù)單個字段（peopleId）來判斷，只留有rowid最小的記錄

1. 
   
2. delete from people
   
3. 
   
4. where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
   
5. 
   
6. and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )>1)

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3、查找表中多余的重復記錄（多個字段）

1. select * from vitae a
   
2. 
   
3. where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)

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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

1. delete from vitae a
   
2. 
   
3. where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)
   
4. 
   
5. and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)

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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

1. select * from vitae a
   
2. 
   
3. where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)
   
4. 
   
5. and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)
   

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