How to retrieve duplicate rows in a table?
How to delete the duplicate entries in a table?

Answers were Sorted based on User's Feedback



How to retrieve duplicate rows in a table? How to delete the duplicate entries in a table?..

Answer / mon

DELETE FROM MyTable
LEFT OUTER JOIN (
SELECT MIN(RowId) as RowId, Col1, Col2, Col3
FROM MyTable
GROUP BY Col1, Col2, Col3
) as KeepRows ON
MyTable.RowId = KeepRows.RowId
WHERE
KeepRows.RowId IS NULL

Is This Answer Correct ?    0 Yes 0 No

How to retrieve duplicate rows in a table? How to delete the duplicate entries in a table?..

Answer / arun kumar k s

drop table #TEMP select distinct * into #TEMP from
TABLE_NAME delete from TABLE_NAME insert into TABLE_NAME
select * from #TEMP

Is This Answer Correct ?    0 Yes 3 No

How to retrieve duplicate rows in a table? How to delete the duplicate entries in a table?..

Answer / gaurav jain

begin
select distinct * into #one from four where id in (select
id from four group by id
having count(*)>1)
delete from four where id in (select id from four group by
id having count(*)>1)
insert into four select * from #one
end

Is This Answer Correct ?    0 Yes 3 No

How to retrieve duplicate rows in a table? How to delete the duplicate entries in a table?..

Answer / anoop rajan

Tbale emp had some duplicate entries and i wanted to retain
the first of all duplicates, the others could be deleted as
follows . Please give your comments if this is the most
optimum way :

delete from emp where rowid in
(select rowid from emp o where rowid !=
(select min(rowid) from emp i where i.empno=o.empno));

Is This Answer Correct ?    0 Yes 3 No

How to retrieve duplicate rows in a table? How to delete the duplicate entries in a table?..

Answer / pawan k. dubey

delete from employee
where Emp_id not in (select min(Emp_id) from employee
group by Emp_Name)

Is This Answer Correct ?    2 Yes 12 No

Post New Answer

More SQL Server Interview Questions

How to compare the top two records using sql?

0 Answers  


Tell me what are the essential components of sql server service broker?

0 Answers  


What is lock escalation and what is its purpose?

0 Answers  


How do I find the sql server database version?

0 Answers  


what is hash table

3 Answers   ILFS, Teledata,






what is the difference in login security modes between v6.5 and 7.0? : Sql server database administration

0 Answers  


What is a mutating table error and how can you get around it?

0 Answers  


How to use copy and concatenate commands in SQL?

0 Answers   Amdocs,


How to replace null values in expressions using isnull()?

0 Answers  


Do you know what is fill factor and pad index?

0 Answers  


Where is trigger in sql server?

0 Answers  


Explain database normalization?

0 Answers  


Categories