Posted by IchBin on 06/25/06 02:04

Geoff Berrow wrote:
> Message-ID: <1151197943.581310.88860@b68g2000cwa.googlegroups.com> from
> frizzle contained the following:
>
>> I'm building a music site with a mysql backend. It has a many to many
>> relational database.
>> I use this to match music genres with certain artists, to maintain the
>> possibility to add multiple genres to a singe artist.
>>
>> Now i've searched google, but can't find a solution on how to update
>> rows with checkboxes.
>> If an artist gets his genre updated as follows:
>> from
>>
>> - [_] classic
>> - [X] rock
>> - [_] ballad
>> - [X] 80's
>> - [_] 90's
>> - etc.
>>
>> to
>>
>> - [_] classic
>> - [_] rock
>> - [_] ballad
>> - [_] 80's
>> - [X] 90's
>> etc.
>>
>> wha t i wonder is how could i best create the backend. it would seem
>> inappropraite to run an update query for each possible box wether it's
>> checked or not.
>
> It depends how you have structured your db. For a many to many
> relationship like this you ideally need three tables, one for artists,
> one for genres and one to link the two.
>
> In the case above you would start with two rows in the link table.
> Updating would require removing a row, though it may be simpler to
> remove them all and then write a new one.
>
>
>

I do not think you need three tables. Genres is an adjective describing
either a song or the singer singer. A Genre should be added to both
tables because each singer could have more that one Genre but one song
can only be one Genre. But then again one song can have multiple singers.


Thanks in Advance...
IchBin, Pocono Lake, Pa, USA http://weconsultants.awardspace.com
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'If there is one, Knowledge is the "Fountain of Youth"'
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