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查询及删除重复记录的SQL数据库语句浅析经常用的网站数据库的自增字段创建具体相关方法汇总
复制具体相关代码 具体相关代码如下:,CREATE TABLE T1 ( id INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITh 1 ,复制具体相关代码 具体相关代码如下:,CREATE TABLE T1 ( id NUMBER(10,0) NOT NULL, ... ); CREATE SEQUENCE T1_ID_SEQ INCREMENT BY 1 ST,复制具体相关代码 具体相关代码如下:,CREATE TABLE T1 ( id INT NOT NULL AUTO_INCREMENT, ... );,复制具体相关代码 具体相关代码如下:,CREATE TABLE T1 ( id SERIAL NOT NULL, ... );,复制具体相关代码 具体相关代码如下:,CREATE TABLE T1 ( id INT NOT NULL IDENTITY, ... );,复制具体相关代码 具体相关代码如下:,CREATE TABLE T1 ( id INT NOT NULL IDENTITY, ... );
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 people
where 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
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)
注:rowid为oracle自带不用该.....
3、查找表中多余的重复记录（多个字段）
select * from vitae a
where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)
4、删除表中多余的重复记录（多个字段），只留有rowid最小的记录
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、查找表中多余的重复记录（多个字段），不包含rowid最小的记录
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)
(二)
比方说
在A表中存在一个字段“name”，
而且不同记录之间的“name”值有可能会相同，
现在就是需要查询出在该表中的各记录之间，“name”值存在重复的项；
Select Name,Count(*) from A Group By Name having Count(*) > 1
假如如果还查性别也相同大则如下:
Select Name,sex,Count(*) from A Group By Name,sex having Count(*) > 1
(三)
具体相关方法一
declare @max integer,@id integer
declare cur_rows cursor local for select 主字段,count(*) from 表名 group by 主字段 having count(*) >； 1
open cur_rows
fetch cur_rows into @id,@max
while @@fetch ...... 关于数据库教程相关的教程网站知识今天我们就说到这里了，希望可以帮到大家。
