如何用sql語句查詢和刪除表中重複數據

時間 2019-11-10

標籤如何 sql 語句查詢刪除表中重複數據欄目 SQL 简体版

原文原文鏈接

一、查詢表中重複數據（單字段） Select * From 表 Where 字段1 In (Select 字段1 From 表 Group By 字段1 Having Count(字段1) > 1) table

二、刪除表中多餘的重複記錄，只留有rowid最小的記錄（單字段） Delete From 表 Where 字段1 In (Select 字段1 From 表 Group By 字段1 Having Count(字段1) > 1) And Rowid Not In (Select Min(Rowid) From 表 Group By 字段1 Having Count(字段1) > 1) select

三、查找表中多餘的重複記錄（多個字段） Select * From 表 a Where (a.字段1, a.字段2) In (Select 字段1, 字段2 From 表 Group By 字段1, 字段2 Having Count(*) > 1) 數據

四、刪除表中多餘的重複記錄，只留有rowid最小的記錄（多個字段） Delete From 表 a Where (a.字段1, a.字段2) In (Select 字段1, 字段2 From 表 Group By 字段1, 字段2 Having Count(*) > 1) And Rowid Not In (Select Min(Rowid) From 表 Group By 字段1, 字段2 Having Count(*) > 1) 查詢

5.刪除多於的重複記錄（單個字段，多個字段） delete from table where id not in ( select min(id) from table group by name) 或者 delete from table where id not in ( select min(id) from table group by 字段1，字段2) tab

6.刪除多餘的重複記錄（單個字段，多個字段） delete from table where id in ( select max(id) from table group by name having count(*)>1) vi

七、查找表中多餘的重複記錄（多個字段），不包含rowid最小的記錄 Select * From 表 a Where (a.字段1, a.字段2) In (Select 字段1, 字段2 From 表 Group By 字段1, 字段2 Having Count(*) > 1) And Rowid Not In (Select Min(Rowid) From 表 Group By 字段1, 字段2 Having Count(*) > 1)co

八、查單個字段的重複次數 Select Name,sex,Count(*) From A Group By Name,sex Having Count(*) > 1let