【澳门金沙vip】Oracle查询表里的重复数据方法

create table TableA ( id varchar(3),customer varchar(5),PhoneNo varchar(6)) insert into TableA select '001','张三','777777' union all select '002','李四','444444' union all select '003','王五','555555' union all select '004','张三','777777' union all select '005','张三','777777' union all select '006','王五','555555'
create table table_new as select distinct * from table1 minuxtruncate table table1;insert into table1 select * from table_new;

SQL重复记录查询 查询多个字段、多表查询、删除重复记录的方法,sql字段

SQL重复记录查询

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) 

例二: 

select * from testtable 
where numeber in (select number from people group by number having count(number) > 1 ) 

可以查出testtable表中number相同的记录  

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) 

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 

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) 

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_status=0 

begin 

select @max = @max -1 

set rowcount @max 

delete from 表名 where 主字段 = @id 

fetch cur_rows into @id,@max 

end 

close cur_rows 

set rowcount 0 

方法二  

有两个意义上的重复记录,一是完全重复的记录,也即所有字段均重复的记录,二是部分关键字段重复的记录,比如Name字段重复,而其他字段不一定重复或都重复可以忽略。  

1、对于第一种重复,比较容易解决,使用 

select distinct * from tableName 

就可以得到无重复记录的结果集。  

如果该表需要删除重复的记录(重复记录保留1条),可以按以下方法删除 

select distinct * into #Tmp from tableName 

drop table tableName 

select * into tableName from #Tmp 

drop table #Tmp 

发生这种重复的原因是表设计不周产生的,增加唯一索引列即可解决。  

2、这类重复问题通常要求保留重复记录中的第一条记录,操作方法如下  

假设有重复的字段为Name,Address,要求得到这两个字段唯一的结果集 

select identity(int,1,1) as autoID, * into #Tmp from tableName 

select min(autoID) as autoID into #Tmp2 from #Tmp group by Name,autoID 

select * from #Tmp where autoID in(select autoID from #tmp2) 

最后一个select即得到了Name,Address不重复的结果集(但多了一个autoID字段,实际写时可以写在select子句中省去此列)  

(四)  

查询重复 

select * from tablename where id in ( 

select id from tablename  

group by id  

having count(id) > 1 

) 

以上就是小编为大家带来的SQL重复记录查询
查询多个字段、多表查询、删除重复记录的方法的全部内容了,希望对大家有所帮助,多多支持帮客之家~

查询多个字段、多表查询、删除重复记录的方法,sql字段 SQL重复记录查询
1、查找表中多余的重复记录,重复记录是根据单…

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) 
Select Name,Count From A Group By Name Having Count  1
select distinct * into #Tmp from tableName drop table tableName select * into tableName from #Tmp drop table #Tmp 
DELETE from 表 WHERE (id) IN ( SELECT id FROM 表 GROUP BY id HAVING COUNT(id)  1) AND ROWID NOT IN (SELECT MIN(ROWID) FROM 表 GROUP BY id HAVING COUNT(*)  1);

结果

delete tab t where t.rowid  ( select min(t2.rowid) from tab t2 where t.col2 = t2.col2 and t.col8 = t2.col8)

2、删除表中多余的重复记录,重复记录是根据单个字段来判断,只留有rowid最小的记录

6、查询出一个表中,某一列的值是相同的SQL:

select * from tablename where id in ( select id from tablename group by id having count(id)  1 )
select * from vitae a where (a.tableId,a.seq) in (select tableId,seq from vitae group by tableId,seq having count(*)  1) and rowid not in (select min(rowid) from vitae group by tableId,seq having count(*)1)

方法一

3、查找表中多余的重复记录

发生这种重复的原因是表设计不周产生的,增加唯一索引列即可解决。

上面的SQL注意:语句非常简单,就是将查询到的数据删除掉。不过这种删除执行的效率非常低,对于大数据量来说,可能会将数据库吊死。

测试环境

delete from table1 a where rowid !=from table1 b where a.name1=b.name1 and a.name2=b.name2……)

例:表中有条六条记录。 其中张三和王五 的记录有重复 TableA

select 字段1,字段2,count(*) from 表名 group by 字段1,字段2 having count(*)  1

4、删除表中多余的重复记录,只留有rowid最小的记录

select * from vitae awhere in  1)and rowid not in from vitae group by peopleId,seq having count1)

三,查询并删除重复记录的SQL语句

5、查找表中多余的重复记录,不包含rowid最小的记录

注:rowid为oracle自带不用该…..

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
delete TableA from TableA Twhereexists( select 1fromtablea where customer=T.customer and phoneno=T.phoneno andid  tt.id)

可以将查询的记录放到临时表中,然后再将原来的表记录删除,最后将临时表的数据导回原来的表中。如下:

select * from vitae a where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*)  1) 
select distinct * into #Tmp from tableNamedrop table tableNameselect * into tableName from #Tmpdrop table #Tmp
id customer PhoneNo 001 张三 777777 002 李四 444444 003 王五 555555 004 张三 777777 005 张三 777777 006 王五 555555 如何写一个sql语句将TableA变成如下 001 张三 777777 002 李四 444444 003 王五 555555

如果想删除一个表的重复数据,可以先建一个临时表,将去掉重复数据后的数据导入到临时表,然后在从临时表将数据导入正式表中,如下:

delete 表名 from 表名 as Twhereexists( select 1from表名 where 字段A=T.字段A and 字段B=T.字段B,(....) and自增列  T.自增列)
delete from 表 a where (a.Id,a.seq) in (select Id,seq from 表 group by Id,seq having count(*)  1) and rowid not in (select min(rowid) from 表 group by Id,seq having count(*)1)
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_status=0 begin select @max = @max -1 set rowcount @max delete from 表名 where 主字段 = @id fetch cur_rows into @id,@max end close cur_rows 

比方说

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

对于完全重复记录的删除

二,删除表中某几个字段的重复

select id from group by id having count(*) 1

该方法适用于有一个字段为自增性,例如本例中的:id

建议先将查询到的重复的数据插入到一个临时表中,然后对进行删除,这样,执行删除的时候就不用再进行一次查询了。如下:

(四) 查询重复

delete from table where tableId in (select tableId from table group by tableId having count(tableId)  1) and rowid not in (select min(rowid) from table group by tableId having count(tableId )1)
select identity(int,1,1) as autoID, * into #Tmp from tableName select min(autoID) as autoID into #Tmp2 from #Tmp group by Name,autoID select * from #Tmp where autoID in(select autoID from #tmp2) 
select * from 表 a where (a.Id,a.seq) in(select Id,seq from 表 group by Id,seq having count(*)  1)
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) 
select * from tablename where id in  1)

一、查询某个字段重复

select * from vitae awhere in  1)

(三)

删除重复数据的基本结构写法:

3、查找表中多余的重复记录

2.group by方法查数据:select count, max from student
–列出重复的记录数,并列出他的name属性group by numhaving count 1
–按num分组后找出表中num列重复,即出现次数大于一次删数据:

Select Name,sex,Count(*) From A Group By Name,sex Having Count(*)  1 
delete from peoplewhere peopleId in  1)and rowid not in from people group by peopleId having count1)
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)

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;

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来判断

oracle查询表中字段里数据是否有重复

5、查找表中多余的重复记录,不包含rowid最小的记录

上面这句话就是建立了临时表,并将查询到的数据插入其中。

select * from people where peopleId in (select peopleId from people group by peopleId having count(peopleId)  1) 

CREATE TABLE 临时表 AS (select 字段1,字段2,count(*) from 表名 group by
字段1,字段2 having count(*) 1)

2、这类重复问题通常要求保留重复记录中的第一条记录,操作方法如下
假设有重复的字段为Name,Address,要求得到这两个字段唯一的结果集

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 * from User u where u.user_name in (select u.user_name from User u group by u.user_name having count(*)  1)
select * from table1 a where rowid !=from table1 b where a.name1=b.name1 and a.name2=b.name2……)