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sql语句查找重复数据

select id, name, memo from A where id in (select id from A group by id having count(1) >= 2) select id, name, memo from A where id in (select id from A group by id having count(1) >= 2)

可用group by……having来实现。 可做如下测试: 1、创建表插入数据: create table test(id int,name varchar(10))insert into test values (1,'张三')insert into test values (2,'李四')insert into test values (3,'张三')insert into test va...

select id from 表名 group by id having count(id) >1

再写个查询就可以了啊 select * from (select distinct column_name from table_name )

方法如下: select * from 你的表名 a where id=(select min(id) from 你的表名 whereitem_id=a.item_id) 在查询之前先把数据库表中的第一行复制到sid里在去,然后让sid和下面的每一行进行比较 取所有相同的行的最小的一下,也可以取最大的,结...

SELECT * FROM tab WHERE C in ( SELECT C FROM tab GROUP BY C HAVING COUNT(A) > 1 )

1、最直观的思路:要知道所有名字有重复人资料,首先必须知道哪个名字重复了: select name from emp group by name having count(*)>1 所有名字重复人的记录是: select * from emp where name in (select name from emp group by name having c...

sql 计算重复数据个数 可以使用 count 来统计 例子 personal表 id name 1 xm 2 xm 3 mx 统计personal表中name为xm的个数 select count(name) total from personal where name='xm' 结果 total 2

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...

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