CODEWITHSUNDEEP
sql-serverduplicatessql-delete
Idan Lahat
Idan Lahat

Reputation: 93

Delete duplicates MS-SQL with minimum date and multiple keys

I have a big table that has duplicates as such:

Example:

1,2,3,20121015

1,2,3,20120101

1,2,3,20110101

2,2,2,20121010

2,2,2,20120101

result should be:

1,2,3,20121015

2,2,2,20121010

I have tried many combinations including group by the primary key with minimum "changeDate" but nothing seems to work perfectly.

I want to have something like this:

delete from table where (number,group.devision,changeDate) not in 
(select from table(number,group,devision,Max(changeDate)) 
group by (number,group.devision)

But I dont think it is a valid MS-SQL syntax.

Your help will be very appreciated!!

Upvotes: 2

Views: 2111

Answers (2)

iruvar
iruvar

Reputation: 23364

The following should work.

delete table from
table inner join (select 
number, group, division, changeDate, row_number() over 
(partition by number, group, division order by changeDate desc) as ranker
from table) Z
on table.number  = Z.number and table.group = Z.group and 
table.changeDate = Z.changeDate and Z.ranker != 1

Upvotes: 0

Martin Smith
Martin Smith

Reputation: 453298

To delete all rows except for the latest for a number, group, Division combination.

;WITH cte
     AS (SELECT ROW_NUMBER() OVER (PARTITION BY number, group, Division 
                                       ORDER BY dateChange DESC) RN
         FROM   YourTable)
DELETE FROM cte
WHERE  RN > 1

Upvotes: 4

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