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Help on delete command

Posted on 2016-11-01
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Last Modified: 2016-11-01
Hello guys

I have a table with three columns

idclie  -   client  - date

I have two rows where id and client are repeated. I want to delete all rows where and let the one row where date is lesser.

how can I do that?

example of rows:

1 - Alexander Garcia - 10/05/2016
1 - Alexander Garcia - 10/03/2016
1 - Alexander Garcia - 21/01/2016

I use the firebird database, but you can send me an example in SQL that I will try it or make some changes to run it in my DB

Thanks
Alexandre
0
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Question by:hidrau
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10 Comments
 
LVL 66

Assisted Solution

by:Jim Horn
Jim Horn earned 164 total points
ID: 41868637
>I have two rows where id and client are repeated. I want to delete all rows where and let the one row where date is lesser.

;with cte as (
   SELECT id, client, ROW_NUMBER() OVER (PARTITION BY id, client ORDER BY [date]) as row_number
   FROM YourTableNameGoesHere) 
DELETE FROM cte WHERE row_number > 1

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Source:  SQL Server Delete Duplicate Rows
1
 
LVL 40

Assisted Solution

by:lcohan
lcohan earned 164 total points
ID: 41868639
Technically they are not duplicated as the "time-stamp" column value you listed is different right? so to leave only 1 out of three put them in a temp table and SELECT TOP 1 * from it where that date is = to whatever you want to keep.
1
 
LVL 13

Assisted Solution

by:Dustin Saunders
Dustin Saunders earned 164 total points
ID: 41868642
You could delete all dupes for one ID, except the highest date with something similar to this:
DELETE FROM table
WHERE id = 1 AND date NOT IN (SELECT TOP 1 date FROM table WHERE id = 1 ORDER BY date)

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LVL 51

Assisted Solution

by:Vitor Montalvão
Vitor Montalvão earned 164 total points
ID: 41868645
(...)let the one row where date is lesser.
Lesser means the more recent or the oldest one?
Anyway you can do it by running the following (replace MAX for MIN and change the '<' to '>' if you want to keep the oldest date):
DELETE FROM tableName
WHERE date < (SELECT MAX(t2.date)
               FROM tableName t2
               WHERE tableName.idclie = t2.idclie)

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NOTE: I didn't test it so please run first in a test environment before running it in Production.
1
 
LVL 52

Accepted Solution

by:
_agx_ earned 1016 total points
ID: 41868651
Edit:  Wow... a lot of responses added while I wrote this up

DELETE FROM dupe
FROM  YourTable dupe
WHERE EXISTS
        (
            SELECT 1
            FROM   YourTable keep
            WHERE  keep.client = dupe.client
            AND    keep.date < dupe.date
        )
1
 
LVL 4

Assisted Solution

by:Steven Kribbe
Steven Kribbe earned 164 total points
ID: 41868693
I do not know the exact table names but i think you want to retain the row with the smallest date. You may want to run this query multiple times because it only deletes the row with the highest date

DELETE TableA
FROM   TableA a
       INNER JOIN (select id, client, max(thedate) as thedate, count(*) group by id, client having count(*) > 1) b
               ON b.id= a.id and b.client = a.client and a.thedate = b.thedate
1
 
LVL 29

Assisted Solution

by:Pawan Kumar
Pawan Kumar earned 164 total points
ID: 41868808
Try..

--

CREATE TABLE testDeleet
(
	 ID INT
	,NMAE VARCHAR(100)
	,Dt DATETIME
)
GO


INSERT INTO testDeleet VALUES

(1 ,'Alexander Garcia' , '05/10/2016'),
(1 ,'Alexander Garcia' , '03/10/2016'),
(1 ,'Alexander Garcia' , '01/21/2016')

GO

--

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Query to delete the duplicate values

---Try 1

--


DELETE j
FROM testDeleet j
WHERE j.Dt <> ANY
             ( 
                SELECT TOP 1 Dt a
                FROM testDeleet e
                WHERE e.ID = j.ID
				ORDER BY e.Dt ASC

             )
 

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O/p

---------------------------

/*------------------------
DELETE j
FROM testDeleet j
WHERE j.Dt <> ANY
             (
                SELECT TOP 1 Dt a
                FROM testDeleet e
                WHERE e.ID = j.ID
                        ORDER BY e.Dt ASC
             )
------------------------*/

(2 row(s) affected)
1
 
LVL 1

Author Closing Comment

by:hidrau
ID: 41868856
thanks all guys.
0
 
LVL 66

Expert Comment

by:Jim Horn
ID: 41868920
>Wow... a lot of responses added while I wrote this up
< Frasier Crane >  When you know the answer it's hard not to hit the buzzer.

Thanks for the split, good luck with your project.
0
 
LVL 52

Expert Comment

by:_agx_
ID: 41868936
< Frasier Crane >  When you know the answer it's hard not to hit the buzzer.

Lol, so true!
0

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