DELETE a FROM transaction_records a WHERE EXISTS(SELECT 1 FROM transaction_records WHERE inpdate='20171224' AND primary_info=a.primary_info AND ID<a.ID);
--其他參考以下:
--处理表重复记录(查询和删除)
/******************************************************************************************
************************************************************
1、Num、Name相同的重复值记录,没有大小关系只保留一条
2、Name相同,ID有大小关系时,保留大或小其中一个记录
日期:2008.06.06
*******************************************************************************************
***********************************************************/
--1、用于查询重复处理记录(如果列没有大小关系时2000用生成自增列和临时表处理,SQL2005用
row_number函数处理)
--> --> (Roy)生成測試數據
if not object_id('Tempdb..#T') is null
drop table #T
Go
Create table #T([ID] int,[Name] nvarchar(1),[Memo] nvarchar(2))
Insert #T
select 1,N'A',N'A1' union all
select 2,N'A',N'A2' union all
select 3,N'A',N'A3' union all
select 4,N'B',N'B1' union all
select 5,N'B',N'B2'
Go
--I、Name相同ID最小的记录(推荐用1,2,3),方法3在SQl05时,效率高于1、2
方法1:
Select * from user a where not exists(select 1 from user where Name=a.Name and ID<a.ID)
方法2:
select a.* from user a join (select min(ID)ID,Name from user group by Name) b on
a.Name=b.Name and a.ID=b.ID
方法3:
select * from user a where ID=(select min(ID) from user where Name=a.Name)
方法4:
select a.* from user a join user b on a.Name=b.Name and a.ID>=b.ID group by
a.ID,a.Name,a.Memo having count(1)=1
方法5:
select * from user a group by ID,Name,Memo having ID=(select min(ID)from user where
Name=a.Name)
方法6:
select * from user a where (select count(1) from user where Name=a.Name and ID<a.ID)=0
方法7:
select * from user a where ID=(select top 1 ID from user where Name=a.name order by ID)
方法8:
select * from user a where ID!>all(select ID from user where Name=a.Name)
方法9(注:ID为唯一时可用):
select * from user a where ID in(select min(ID) from user group by Name)
--SQL2005:
方法10:
select ID,Name,Memo from (select *,min(ID)over(partition by Name) as MinID from user a)T
where ID=MinID
方法11:
select ID,Name,Memo from (select *,row_number()over(partition by Name order by ID) as MinID
from user a)T where MinID=1
生成结果:
/*
ID Name Memo
----------- ---- ----
1 A A1
4 B B1
(2 行受影响)
*/
--II、Name相同ID最大的记录,与min相反:
方法1:
Select * from user a where not exists(select 1 from user where Name=a.Name and ID>a.ID)
方法2:
select a.* from user a join (select max(ID)ID,Name from user group by Name) b on
a.Name=b.Name and a.ID=b.ID order by ID
方法3:
select * from user a where ID=(select max(ID) from user where Name=a.Name) order by ID
方法4:
select a.* from user a join user b on a.Name=b.Name and a.ID<=b.ID group by
a.ID,a.Name,a.Memo having count(1)=1
方法5:
select * from user a group by ID,Name,Memo having ID=(select max(ID)from user where
Name=a.Name)
方法6:
select * from user a where (select count(1) from user where Name=a.Name and ID>a.ID)=0
方法7:
select * from user a where ID=(select top 1 ID from user where Name=a.name order by ID
desc)
方法8:
select * from user a where ID!<all(select ID from user where Name=a.Name)
方法9(注:ID为唯一时可用):
select * from user a where ID in(select max(ID) from user group by Name)
--SQL2005:
方法10:
select ID,Name,Memo from (select *,max(ID)over(partition by Name) as MinID from user a)T
where ID=MinID
方法11:
select ID,Name,Memo from (select *,row_number()over(partition by Name order by ID desc) as
MinID from user a)T where MinID=1
生成结果2:
/*
ID Name Memo
----------- ---- ----
3 A A3
5 B B2
(2 行受影响)
*/
--2、删除重复记录有大小关系时,保留大或小其中一个记录
--> --> (Roy)生成測試數據
if not object_id('Tempdb..user') is null
drop table user
Go
Create table user([ID] int,[Name] nvarchar(1),[Memo] nvarchar(2))
Insert user
select 1,N'A',N'A1' union all
select 2,N'A',N'A2' union all
select 3,N'A',N'A3' union all
select 4,N'B',N'B1' union all
select 5,N'B',N'B2'
Go
--I、Name相同ID最小的记录(推荐用1,2,3),保留最小一条
方法1:
delete a from user a where exists(select 1 from user where Name=a.Name and ID<a.ID)
方法2:
delete a from user a left join (select min(ID)ID,Name from user group by Name) b on
a.Name=b.Name and a.ID=b.ID where b.Id is null
方法3:
delete a from user a where ID not in (select min(ID) from user where Name=a.Name)
方法4(注:ID为唯一时可用):
delete a from user a where ID not in(select min(ID)from user group by Name)
方法5:
delete a from user a where (select count(1) from user where Name=a.Name and ID<a.ID)>0
方法6:
delete a from user a where ID<>(select top 1 ID from user where Name=a.name order by ID)
方法7:
delete a from user a where ID>any(select ID from user where Name=a.Name)
select * from user
生成结果:
/*
ID Name Memo
----------- ---- ----
1 A A1
4 B B1
(2 行受影响)
*/
--II、Name相同ID保留最大的一条记录:
方法1:
delete a from user a where exists(select 1 from user where Name=a.Name and ID>a.ID)
方法2:
delete a from user a left join (select max(ID)ID,Name from user group by Name) b on
a.Name=b.Name and a.ID=b.ID where b.Id is null
方法3:
delete a from user a where ID not in (select max(ID) from user where Name=a.Name)
方法4(注:ID为唯一时可用):
delete a from user a where ID not in(select max(ID)from user group by Name)
方法5:
delete a from user a where (select count(1) from user where Name=a.Name and ID>a.ID)>0
方法6:
delete a from user a where ID<>(select top 1 ID from user where Name=a.name order by ID
desc)
方法7:
delete a from user a where ID<any(select ID from user where Name=a.Name)
select * from user
/*
ID Name Memo
----------- ---- ----
3 A A3
5 B B2
(2 行受影响)
*/
--3、删除重复记录没有大小关系时,处理重复值
--> --> (Roy)生成測試數據
if not object_id('Tempdb..user') is null
drop table user
Go
Create table user([Num] int,[Name] nvarchar(1))
Insert user
select 1,N'A' union all
select 1,N'A' union all
select 1,N'A' union all
select 2,N'B' union all
select 2,N'B'
Go
方法1:
if object_id('Tempdb..#') is not null
drop table #
Select distinct * into # from user--排除重复记录结果集生成临时表#
truncate table user--清空表
insert user select * from # --把临时表#插入到表user中
--查看结果
select * from user
/*
Num Name
----------- ----
1 A
2 B
(2 行受影响)
*/
--重新执行测试数据后用方法2
方法2:
alter table user add ID int identity--新增标识列
go
delete a from user a where exists(select 1 from user where Num=a.Num and Name=a.Name and
ID>a.ID)--只保留一条记录
go
alter table user drop column ID--删除标识列
--查看结果
select * from user
/*
Num Name
----------- ----
1 A
2 B
(2 行受影响)
*/
--重新执行测试数据后用方法3
方法3:
declare Roy_Cursor cursor local for
select count(1)-1,Num,Name from user group by Num,Name having count(1)>1
declare @con int,@Num int,@Name nvarchar(1)
open Roy_Cursor
fetch next from Roy_Cursor into @con,@Num,@Name
while @@Fetch_status=0
begin
set rowcount @con;
delete user where Num=@Num and Name=@Name
set rowcount 0;
fetch next from Roy_Cursor into @con,@Num,@Name
end
close Roy_Cursor
deallocate Roy_Cursor
--查看结果
select * from user
/*
Num Name
----------- ----
1 A
2 B
(2 行受影响)
#方法1:
SELECT * FROM customer a WHERE a.customer_realname='李海锋' AND NOT EXISTS(SELECT 1 FROM
customer WHERE customer_realname=a.customer_realname AND customer_id>a.customer_id AND
customer_realname='李海锋')
#方法2:
SELECT a.* FROM customer a JOIN (SELECT MAX(customer_id) AS customer_id FROM customer
WHERE customer_realname='李海锋'GROUP BY customer_realname) b ON
a.customer_id=b.customer_id ORDER BY customer_id
#方法3:
SELECT a.* FROM customer a WHERE a.customer_realname='李海锋' AND a.customer_id=(SELECT
MAX(b.customer_id) FROM customer b WHERE b.customer_realname=a.custo
相关推荐
查询及删除oracle重复记录的SQL语句
plsql删除重复记录
删除重复记录 删除数据表中的重复记录,包括MySQL、SQL Server、Oracle等
SQL重复记录查询与删除 过滤重复字记录,单字段重复,重复的只显示1条记录,并且显示出所有字段 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 只能显示哪些记录是重复的。 2、删除表中...
本文主要给大家介绍了关于MySQL中查询、删除重复记录的方法,分享出来供大家参考学习,下面来看看详细的介绍: 查找所有重复标题的记录: select title,count(*) as count from user_table group by title having ...
使用Oracle查询并删除重复记录的SQL语句
Oracle查询重复数据与删除重复记录方法,Oracle查询重复数据与删除重复记录方法
在Access中一般只能查找10行大概20条重复记录,这样程序就可以任意指定表及多字段检索重复记录,并把重复的记录移除到一个临时表中,并不是进行真正删除,你可以进行恢复。但是执行第二次查找时则自动删除上次查找的...
SQL语句查询所有的重复记录,删除所有的重复记录,查找指定的重复记录
sql查询表中某字段下所有重复的记录,删除某字段下重复记录最小的那笔记录
在Access中一般只能查找10行大概20条重复记录,这样程序就可以任意指定表及多字段检索重复记录,并把重复的记录移除到一个临时表中,并不是进行真正删除,你可以进行恢复。但是执行第二次查找时则自动删除上次查找的...
查询及删除重复记录的SQL语句1、查找表中多余的重复记录,重复记录是根据单个字段(Id)来判断select * from 表 where Id in (select Id from 表 group by Id having count(Id) > 1)2、删除表中多余的重复记录,...
oracle中 ,如何删除重复的记录信息
by语句删除重复并保持一条重复记录,解决数据集中有重复记录的问题
查询SQL重复记录的几种方法总结,删除SQL重复记录查
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) >...
MySQL删除重复记录方法。
最高效的删除重复记录方法
删除重复记录的方法原理:在Oracle中,每一条记录都有一个rowid,rowid在整个数据库中是唯一的,rowid确定了每条记录是在Oracle中的哪一个数据文件、块、行上。在重复的记录中,可能所有列的内容都相同,但rowid不会...
最基本的四种SQL语句删除重复记录的方法