在SQL Server中查找重复的行

Question

我有一个组织的SQL Server数据库,并且有许多重复的行.我想运行一个select语句来获取所有这些和dupes的数量,但也返回与每个组织关联的id.

声明如下:

SELECT     orgName, COUNT(*) AS dupes  
FROM         organizations  
GROUP BY orgName  
HAVING      (COUNT(*) > 1)

将返回类似的东西

orgName        | dupes  
ABC Corp       | 7  
Foo Federation | 5  
Widget Company | 2 

但我也想抓住他们的身份证.有没有办法做到这一点？也许就像一个

orgName        | dupeCount | id  
ABC Corp       | 1         | 34  
ABC Corp       | 2         | 5  
...  
Widget Company | 1         | 10  
Widget Company | 2         | 2  

原因是还有一个单独的用户表链接到这些组织,我想统一它们(因此删除欺骗,以便用户链接到同一组织而不是欺骗组织).但我想手动分配,所以我不会搞砸任何东西,但我仍然需要一个声明返回所有欺骗组织的ID,以便我可以浏览用户列表.

Answer 1

select o.orgName, oc.dupeCount, o.id
from organizations o
inner join (
    SELECT orgName, COUNT(*) AS dupeCount
    FROM organizations
    GROUP BY orgName
    HAVING COUNT(*) > 1
) oc on o.orgName = oc.orgName

Answer 2

您可以运行以下查询并查找重复项max(id)并删除这些行.

SELECT orgName, COUNT(*), Max(ID) AS dupes 
FROM organizations 
GROUP BY orgName 
HAVING (COUNT(*) > 1)

但是你必须运行几次这个查询.

Answer 3

你可以这样做:

SELECT
    o.id, o.orgName, d.intCount
FROM (
     SELECT orgName, COUNT(*) as intCount
     FROM organizations
     GROUP BY orgName
     HAVING COUNT(*) > 1
) AS d
    INNER JOIN organizations o ON o.orgName = d.orgName

如果您只想返回可以删除的记录(只留下其中一个),您可以使用:

SELECT
    id, orgName
FROM (
     SELECT 
         orgName, id,
         ROW_NUMBER() OVER (PARTITION BY orgName ORDER BY id) AS intRow
     FROM organizations
) AS d
WHERE intRow != 1

编辑:SQL Server 2000没有ROW_NUMBER()函数.相反,你可以使用:

SELECT
    o.id, o.orgName, d.intCount
FROM (
     SELECT orgName, COUNT(*) as intCount, MIN(id) AS minId
     FROM organizations
     GROUP BY orgName
     HAVING COUNT(*) > 1
) AS d
    INNER JOIN organizations o ON o.orgName = d.orgName
WHERE d.minId != o.id

Answer 4

标记为正确的解决方案对我不起作用,但我发现这个答案非常有用:获取MySql中重复行的列表

SELECT n1.* 
FROM myTable n1
INNER JOIN myTable n2 
ON n2.repeatedCol = n1.repeatedCol
WHERE n1.id <> n2.id

Answer 5

你可以尝试这个,它最适合你

 WITH CTE AS
    (
    SELECT *,RN=ROW_NUMBER() OVER (PARTITION BY orgName ORDER BY orgName DESC) FROM organizations 
    )
    select * from CTE where RN>1
    go

Answer 6

select * from [Employees]

查找重复记录1）使用CTE

with mycte
as
(
select Name,EmailId,ROW_NUMBER() over(partition by Name,EmailId order by id) as Duplicate from [Employees]
)
select * from mycte

2）通过使用GroupBy

select Name,EmailId,COUNT(name) as Duplicate from  [Employees] group by Name,EmailId 

Answer 7

如果要删除重复项：

WITH CTE AS(
   SELECT orgName,id,
       RN = ROW_NUMBER()OVER(PARTITION BY orgName ORDER BY Id)
   FROM organizations
)
DELETE FROM CTE WHERE RN > 1