Deleting the duplicate values in a column

--000e0ce0b492f02eae04a2d6c94a
Content-Type: text/plain; charset=ISO-8859-1

hi,
If we have a following mysql table:
Name - ids
A 1
B 1
C 2
D 3

I want to remove all duplicate occurances and have a result like
Name - ids
C 2
D 3

how can i do that with a query in mysql

Pl. help asap
--
Thanks and kind Regards,
Abhishek jain

--000e0ce0b492f02eae04a2d6c94a--
abhishek.netjain [ Mo, 09 Mai 2011 14:15 ] [ ID #2059281 ]

Re: Deleting the duplicate values in a column

SELECT * from <table> group by id having count =3D 1;

On May 9, 2011, at 5:45 PM, abhishek jain wrote:

> hi,
> If we have a following mysql table:
> Name - ids
> A 1
> B 1
> C 2
> D 3
>
> I want to remove all duplicate occurances and have a result like
> Name - ids
> C 2
> D 3
>
> how can i do that with a query in mysql
>
> Pl. help asap
> --
> Thanks and kind Regards,
> Abhishek jain


--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/mysql?unsub=3Dgcdmg-mysql-2 [at] m.gmane.o rg
Aveek Misra [ Mo, 09 Mai 2011 16:24 ] [ ID #2059282 ]

Re: Deleting the duplicate values in a column

Sorry I jumped the gun, didn't realize it was a delete. The problem is that=
GROUP BY does not work with DELETE. You can try this:

DELETE FROM <mytable> where id IN (SELECT id from <my table> GROUP BY id HA=
VING COUNT(*) > 1);

Not sure whether this will work though. You can always use a temp table for=
this purpose although that is not so appealing as doing it in one query

CREATE TABLE tmp LIKE <mytable>;
INSERT INTO tmp SELECT * from <my table> GROUP BY id HAVING COUNT(*) =3D 1;
DROP TABLE <mytable>;
RENAME TABLE tmp TO <mytable>;


Thanks
Aveek

On May 9, 2011, at 7:54 PM, Aveek Misra wrote:

> SELECT * from <table> group by id having count =3D 1;
>
> On May 9, 2011, at 5:45 PM, abhishek jain wrote:
>
>> hi,
>> If we have a following mysql table:
>> Name - ids
>> A 1
>> B 1
>> C 2
>> D 3
>>
>> I want to remove all duplicate occurances and have a result like
>> Name - ids
>> C 2
>> D 3
>>
>> how can i do that with a query in mysql
>>
>> Pl. help asap
>> --
>> Thanks and kind Regards,
>> Abhishek jain
>
>
> --
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe: http://lists.mysql.com/mysql?unsub=3Daveekm [at] yahoo-inc.=
com
>


--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/mysql?unsub=3Dgcdmg-mysql-2 [at] m.gmane.o rg
Aveek Misra [ Mo, 09 Mai 2011 16:43 ] [ ID #2059283 ]
Datenbanken » gmane.comp.db.mysql.general » Deleting the duplicate values in a column

Vorheriges Thema: Fwd: DBCP error
Nächstes Thema: MySQL Community Server 5.5.12 has been released