Delete duplicate records from the table?(Table must have
unique id)

Answers were Sorted based on User's Feedback



Delete duplicate records from the table?(Table must have unique id)..

Answer / dinesh kumar

delete from emp where id Not in(select max(id) id from emp
group by name having count(id)>1)

Is This Answer Correct ?    22 Yes 9 No

Delete duplicate records from the table?(Table must have unique id)..

Answer / lince

DELETE
FROM MyTable
WHERE ID IN
(
SELECT MAX(ID)
FROM MyTable
GROUP BY DuplicateColumn1 HAVING COUNT(ID)>1
)

Is This Answer Correct ?    4 Yes 2 No

Delete duplicate records from the table?(Table must have unique id)..

Answer / manoj

Check following blog post on how to first identify & then delete duplicate records: http://sqlwithmanoj.wordpress.com/2011/10/14/identify-delete-duplicate-records-from-a-table/


This lists multiple ways to delete duplicates.

Is This Answer Correct ?    2 Yes 0 No

Delete duplicate records from the table?(Table must have unique id)..

Answer / kk

DELETE
FROM MyTable
WHERE ID NOT IN
(
SELECT MAX(ID)
FROM MyTable
GROUP BY DuplicateColumn1, DuplicateColumn2, DuplicateColumn3)

Is This Answer Correct ?    7 Yes 7 No

Delete duplicate records from the table?(Table must have unique id)..

Answer / naren

delete id from table where id in(select id from table having count(id)>1)

Is This Answer Correct ?    1 Yes 2 No

Delete duplicate records from the table?(Table must have unique id)..

Answer / krishna

select *
from mytable b
join
(
select Duplicatecolumn,MAX(id) id
from mytable
group by Duplicatecolumn
) b1 on b.Duplicatecolumn = b1.Duplicatecolumn
where b.id <> b1.id

Is This Answer Correct ?    0 Yes 1 No

Delete duplicate records from the table?(Table must have unique id)..

Answer / brijesh darmwal, sandhya

DELETE FROM [MyDb].[dbo].[sandhya]
WHERE id
IN
(SELECT id
FROM
(SELECT MAX(id) as id,name,addr
FROM [MyDb].[dbo].[sandhya] GROUP BY name,addr having
count(id)>=2)
Tmp)

Is This Answer Correct ?    7 Yes 16 No

Post New Answer

More SQL Server Interview Questions

please tell me the query to get details of the employee having the second largest salary

11 Answers   247Customer,


If we delete pack Spec what will be the status of pack Body ?

0 Answers   Nagarro,


How to find out what is the default collation in a database?

0 Answers  


What is the filtered index?

0 Answers  


How to update values in a table with update statements in ms sql server?

0 Answers  


sql database suspect We have a sql database that is showing as suspect. How can we recover?

0 Answers  


I have to display ten columns values from diffrent ten tables. how many joins are require?

10 Answers   CarrizalSoft Technologies, HCL,


 Explain what is sql override for a source taLle in a mapping?

0 Answers   Informatica,


What is the simplest way to create a new database in ms sql server?

0 Answers  


What is a subquery in a select query statement in ms sql server?

0 Answers  


Relational calculus is what type of language?

0 Answers   HCL,


Do you know what are the restrictions that views have to follow?

0 Answers  


Categories