形容记录重复的诗句

时间：2020-02-06 17:18

如何查询不重复的记录比如 A 列里面很多重复的记录我只要列出重复记录中的一个就行了命令如何写

SQL code--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******************************************************************************************************************************************************\\\/--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)生成测试数据if not object_id('Tempdb..#T') is null drop table #TGoCreate table #T([ID] int,[Name] nvarchar(1),[Memo] nvarchar(2))Insert #Tselect 1,N'A',N'A1' union allselect 2,N'A',N'A2' union allselect 3,N'A',N'A3' union allselect 4,N'B',N'B1' union allselect 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 #T a where not exists(select 1 from #T where Name=a.Name and ID=b.ID group by a.ID,a.Name,a.Memo having count(1)=1 方法5:select * from #T a group by ID,Name,Memo having ID=(select min(ID)from #T where Name=a.Name)方法6:select * from #T a where (select count(1) from #T where Name=a.Name and IDall(select ID from #T where Name=a.Name)方法9(注:ID为唯一时可用):select * from #T a where ID in(select min(ID) from #T group by Name)--SQL2005:方法10:select ID,Name,Memo from (select *,min(ID)over(partition by Name) as MinID from #T 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 #T a)T where MinID=1生成结果:\\\/*ID Name Memo----------- ---- ----1 A A14 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 #T a where not exists(select 1 from #T where Name=a.Name and ID>a.ID)方法2:select a.* from #T a join (select max(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID order by ID方法3:select * from #T a where ID=(select max(ID) from #T where Name=a.Name) order by ID方法4:select a.* from #T a join #T 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 #T a group by ID,Name,Memo having ID=(select max(ID)from #T where Name=a.Name)方法6:select * from #T a where (select count(1) from #T where Name=a.Name and ID>a.ID)=0方法7:select * from #T a where ID=(select top 1 ID from #T where Name=a.name order by ID desc)方法8:select * from #T a where ID!

求一条sql语句,关于查询重复记录

select org_id from 表 where date ='20071010'或者select org_id from 表 where date=(select date 表 group by date having count(date)>3)

请高手帮助写一个删除重复记录的sql语句

主键都一样的话建议你导入到另一个表，在导回来就没有了

如何统计符合多个条件的记录的不重复记录的数量

不知道你什么数据库.如果数据库支持 ROW_NUMBER() 函数的话, 倒是很省事的.-- 首先创建测试表CREATE TABLE test_delete( name varchar(10), value INT);go-- 测试数据，其中张三100 与王五80 是完全一样的INSERT INTO test_deleteSELECT '张三', 100UNION ALL SELECT '张三', 100UNION ALL SELECT '李四', 80UNION ALL SELECT '王五', 80UNION ALL SELECT '王五', 80UNION ALL SELECT '赵六', 90UNION ALL SELECT '赵六', 70go-- 首先查询一下， ROW_NUMBER 效果是否满足预期SELECT ROW_NUMBER() OVER (PARTITION BY name, value ORDER BY (SELECT 1) ) AS no, name, valueFROM test_deleteno name value----- ---------- ----------- 1 李四 80 1 王五 80 2 王五 80 1 张三 100 2 张三 100 1 赵六 70 1 赵六 90从结果上可以看到，如果有重复的，完全一样的话， no 是有大于1的。

几个删除重复记录的SQL语句