導(dǎo)讀:1建站知識(shí)SQL重復(fù)記錄查詢的幾種方法，需要的朋友可以參考一下營(yíng)銷型網(wǎng)站建設(shè)網(wǎng)seo優(yōu)化趨勢(shì)。

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

復(fù)制代碼 代碼如下:

select * from peoplewhere peopleId in (select peopleId from people group by peopleId having count

(peopleId) > 1)

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

復(fù)制代碼 代碼如下:

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(fù)記錄（多個(gè)字段）

復(fù)制代碼 代碼如下:

select * from vitae awhere (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(fù)記錄（多個(gè)字段），只留有rowid最小的記錄

復(fù)制代碼 代碼如下:

delete 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)

5、查找表中多余的重復(fù)記錄（多個(gè)字段），不包含rowid最小的記錄

復(fù)制代碼 代碼如下:

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)seo網(wǎng)站優(yōu)化軟件

(二)比方說在A表中存在一個(gè)字段“name”，而且不同記錄之間的“name”值有可能會(huì)相同，現(xiàn)在就是需要查詢出在該表中的各記錄之間，“name”值存在重復(fù)的項(xiàng)；

復(fù)制代碼 代碼如下:

Select Name,Count(*) From A Group By Name Having Count(*) > 1

如果還查性別也相同大則如下:

復(fù)制代碼 代碼如下:

Select Name,sex,Count(*) From A Group By Name,sex Having Count(*) > 1

(三)方法一

復(fù)制代碼 代碼如下:

declare @max integer,@id integerdeclare cur_rows cursor local for select 主字段,count(*) from 表名 group by 主字段 having

count(*) >； 1open cur_rowsfetch cur_rows into @id,@maxwhile @@fetch_status=0beginselect @max = @max -1set rowcount @maxdelete from 表名 where 主字段 = @idfetch cur_rows into @id,@maxendclose cur_rowsset rowcount 0

方法二

　　有兩個(gè)意義上的重復(fù)記錄，一是完全重復(fù)的記錄，也即所有字段均重復(fù)的記錄，二是部分關(guān)鍵字段重

復(fù)的記錄，比如Name字段重網(wǎng)站seo優(yōu)化培訓(xùn)復(fù)，而其他字段不一定重復(fù)或都重復(fù)可以忽略。

　　1、對(duì)于第一種重復(fù)，比較容易解決，使用

關(guān)鍵詞標(biāo)簽: 標(biāo)簽 SQL 幾種方法