Question

我的数据库中有这个表：

tblAgencies
----------------------
AgencyID (PK)
VendorID
RegionID
Name
Zip

长话短说，我不小心将我的整个表复制到自身 - 所以我表中的每一行都有重复。

但是我的AgencyID字段是标识，并且自动递增，我需要根据所有其他字段查找重复项，因为AgencyID是唯一的。

有谁知道我该怎么做？

Answer 1

这将保留最旧的AgencyID值，否则删除任何重复项。

;WITH x AS 
(
  SELECT *, rn = ROW_NUMBER() OVER 
    (PARTITION BY VendorID, RegionID, Name, Zip
    ORDER BY AgencyID) FROM dbo.tblAgencies
)
DELETE x WHERE rn > 1;

但是，要小心;如果其他表引用了AgencyID 和，他们已经获得了任何较新的，错误的值，这可能无效。

Answer 2

最简单的解决方案，将select distinct用于临时表，然后重新加载原始

Answer 3

如果所有其他列的组合都是唯一的，则此查询将为您提供重复项：

select * from mytable t1
where exists
         (select * from mytable t2 
         where t1.VendorID = t2.VendorID 
         and t1.RegionID = t2.RegionID 
         and and t1.Name = t2.Name 
         and t1.Zip = t2.Zip 
         and t1.AgencyID > t2.AgencyID)

Answer 4

除了最小的agencyid行外，这应该为您提供具有重复值的所有行。

select *
  from tblAgencies
  where AgencyID not in (select min(AgencyID)
                           from tblAgencies
                           group by VendorID, RegionID, Name, Zip)

编辑：添加SQLFiddle

Answer 5

;with CTE 
AS
 (
   SELECT ID_Column, rn = ROW_NUMBER() OVER (PARTITION BY Column1, Column2, Column3... ORDER BY ID ASC)
  FROM T
)
DELETE FROM CTE 
WHERE rn >= 2

Answer 6

;with CTE 
AS
(SELECT MAX(AgencyID) AgentID,VendorID ,
RegionID ,
Name ,
Zip  FROM tblAgencies
GROUP BY VendorID ,
RegionID ,
Name ,
Zip 
HAVING COUNT(*) > 1)

DELETE FROM tblAgencies WHERE  EXISTS  (SELECT 1 FROM CTE
WHERE  AgentID = tblAgencies.AgencyID)

Answer 7

很多答案会在这里给你你想要的东西，但是没有必要使用CTE或进行任何分组，最简单的方法就是：

delete   t1
from     tblAgencies t1
join     tblAgencies t2
on       t1.VendorId = t2.VendorId
and      t1.RegionId = t2.RegionId
and      t1.Name = t2.Name
and      t1.Zip = t2.Zip
and      t1.AgencyId > t2.AgencyId

Answer 8

也许这会有所帮助：How to delete duplicates in the presence of a primary key?

删除不基于主键的重复行

8 个答案: