我有一个组织的SQL Server数据库,有许多重复的行。我想运行一个选择语句来获取所有这些和被欺骗的数量,同时还返回与每个组织相关的id。

这样的陈述:

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

将返回如下内容

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

但我也想要他们的id。有什么办法可以做到吗?也许就像

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,我想把它们统一起来(因此删除dupes,用户链接到同一个组织,而不是dupe组织)。但我想手动部分,所以我不会搞砸任何事情,但我仍然需要一个语句返回所有的dupe组织的id,这样我就可以通过用户列表。


当前回答

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

其他回答

select orgname, count(*) as dupes, id 
from organizations
where orgname in (
    select orgname
    from organizations
    group by orgname
    having (count(*) > 1)
)
group by orgname, id
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

假设我们有一个表'Student',有两列:

student_id int student_name varchar 记录: +------------+---------------------+ | student_id | student_name | +------------+---------------------+ | 101 | usman | | 101 | usman | | 101 | usman | | 102 | usmanyaqoob | | 103 | muhammadusmanyaqoob | | 103 | muhammadusmanyaqoob | +------------+---------------------+

现在我们希望看到重复的记录 使用这个查询:

select student_name,student_id ,count(*) c from student group by student_id,student_name having c>1;

+---------------------+------------+---+
| student_name        | student_id | c |
+---------------------+------------+---+
| usman               |        101 | 3 |
| muhammadusmanyaqoob |        103 | 2 |
+---------------------+------------+---+

有几种方法可以选择重复的行。

对于我的解决方案,首先考虑以下表格为例

CREATE TABLE #Employee
(
ID          INT,
FIRST_NAME  NVARCHAR(100),
LAST_NAME   NVARCHAR(300)
)

INSERT INTO #Employee VALUES ( 1, 'Ardalan', 'Shahgholi' );
INSERT INTO #Employee VALUES ( 2, 'name1', 'lname1' );
INSERT INTO #Employee VALUES ( 3, 'name2', 'lname2' );
INSERT INTO #Employee VALUES ( 2, 'name1', 'lname1' );
INSERT INTO #Employee VALUES ( 3, 'name2', 'lname2' );
INSERT INTO #Employee VALUES ( 4, 'name3', 'lname3' );

第一个解决方案:

SELECT DISTINCT *
FROM   #Employee;

WITH #DeleteEmployee AS (
                     SELECT ROW_NUMBER()
                            OVER(PARTITION BY ID, First_Name, Last_Name ORDER BY ID) AS
                            RNUM
                     FROM   #Employee
                 )

SELECT *
FROM   #DeleteEmployee
WHERE  RNUM > 1

SELECT DISTINCT *
FROM   #Employee

第二个解决方案:使用标识字段

SELECT DISTINCT *
FROM   #Employee;

ALTER TABLE #Employee ADD UNIQ_ID INT IDENTITY(1, 1)

SELECT *
FROM   #Employee
WHERE  UNIQ_ID < (
    SELECT MAX(UNIQ_ID)
    FROM   #Employee a2
    WHERE  #Employee.ID = a2.ID
           AND #Employee.FIRST_NAME = a2.FIRST_NAME
           AND #Employee.LAST_NAME = a2.LAST_NAME
)

ALTER TABLE #Employee DROP COLUMN UNIQ_ID

SELECT DISTINCT *
FROM   #Employee

所有解决方案的最后使用这个命令

DROP TABLE #Employee

我使用两个方法来查找重复的行。 第一种方法是最著名的用分组的方法。 第二种方法是使用CTE -公共表表达式。

正如@RedFilter提到的那样,这种方式也是正确的。很多时候我发现CTE方法对我也很有用。

WITH TempOrg (orgName,RepeatCount)
AS
(
SELECT orgName,ROW_NUMBER() OVER(PARTITION by orgName ORDER BY orgName) 
AS RepeatCount
FROM dbo.organizations
)
select t.*,e.id from organizations   e
inner join TempOrg t on t.orgName= e.orgName
where t.RepeatCount>1

在上面的例子中,我们通过使用ROW_NUMBER和PARTITION by找到重复出现的情况来收集结果。然后应用where子句只选择重复次数大于1的行。将所有结果收集到CTE表中,并与Organizations表进行联接。

来源:CodoBee