how to find nested dupes

I have a query problem.

There can be dupes in machine - no problem
There can be dupes in owner - no problem

but I like to find out whether there are machine dupes of the same owner

this are the contents of the table

owner,machine
--------------------
michael,car
brad,car
jeniffer,laptop
john,car
john,car
john,laptop
brad,laptop


I like to do a query to john with result:
car

If i do the same to brad I get an empty result.

Can anybody help please me with this?

Thanks in advance

Jaak wrote:
> I have a query problem.
>
> There can be dupes in machine - no problem
> There can be dupes in owner - no problem
>
> but I like to find out whether there are machine dupes of the same owner
>
> this are the contents of the table
>
> owner,machine
> --------------------
> michael,car
> brad,car
> jeniffer,laptop
> john,car
> john,car
> john,laptop
> brad,laptop
>
>
> I like to do a query to john with result:
> car
>
> If i do the same to brad I get an empty result.
>
> Can anybody help please me with this?

Something like this?

SELECT count(*), owner, machine FROM table1 group by owner, machine

--
Justin Koivisto, ZCE - justin@koivi.com
http://koivi.com

"Justin Koivisto" <justin@koivi.com> schreef in bericht
news:rradnZ8mEsFRbF_eRVn-hA@onvoy.com...
> Jaak wrote:
>> I have a query problem.
>>
>> There can be dupes in machine - no problem
>> There can be dupes in owner - no problem
>>
>> but I like to find out whether there are machine dupes of the same owner
>>
>> this are the contents of the table
>>
>> owner,machine
>> --------------------
>> michael,car
>> brad,car
>> jeniffer,laptop
>> john,car
>> john,car
>> john,laptop
>> brad,laptop
>>
>>
>> I like to do a query to john with result:
>> car
>>
>> If i do the same to brad I get an empty result.
>>
>> Can anybody help please me with this?
>
> Something like this?
>
> SELECT count(*), owner, machine FROM table1 group by owner, machine
No, its intended for finding out wheter there are duplicate records
so I can delete them afterwards

Jaak wrote:
> I have a query problem.
>
> There can be dupes in machine - no problem
> There can be dupes in owner - no problem
>
> but I like to find out whether there are machine dupes of the same owner
>
> this are the contents of the table
>
> owner,machine
> --------------------
> michael,car
> brad,car
> jeniffer,laptop
> john,car
> john,car
> john,laptop
> brad,laptop
>
>
> I like to do a query to john with result:
> car
>
> If i do the same to brad I get an empty result.
>
> Can anybody help please me with this?
>
> Thanks in advance
>
>
>
Try a 2 field index?