Re: gEDA-user: database driven component chooser - part II

[Levente <leventelist@xxxxxxxxx>]

Christoph Lechner <cl0023@xxxxxxx> wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Levente wrote:
>> Duncan Drennan <duncan.drennan@xxxxxxxxx> wrote:
>>>> I'm back from Stuttgart where I could hack a bit on my database stuff.
>>>> Now, I have a command line SQL client, which can be used as a chooser. It
>>>> takes command line arguments as search parameters, and makes an SQL query, and
>>>> prints the result.
>>> Levente, where could I find out more about what exactly your programme does?
>> 
>> I am about to write a README for it, and check it into my CVS repository, but
>> my washingmachine died, so I have to go to my parents to do the whashing.
>> 
>> But in a nutshell, it looks up a component from a mySQL database, and
>> parse the result. The database is online, and so you can see what is
>> inside.
> OK. I took a look at the database. So a question came to mind when I saw
> the layout of the 'device' table:
> Why do you store the relationship between entries in the 'device' table
> and entries in the 'supplier' table in fields named supplier*,
> ordering_code*, price* in the 'device' table? What if there are more
> than 3 suppliers for any given part?
> 
> As the relation between 'device' and 'supplier' is a many-many
> relationship, you'd be better off creating just another table, holding
> the device's ID, the ID of the supplier and fields for the ordering_code
> and the price. Then you only need to LEFT JOIN the tables
> rel-device-supplier and supplier and you get all suppliers for a given
> part. This would give you a somewhat tidier DB layout ...

This is a good point, and my client code doesn't need so much tweek to
implement this. I think it doesn't need any, hence it is a component chooser.

But sure this method gives much more flexibility on the supplier business.

Thank you very much for your comment!

-- 
Levente
http://web.interware.hu/lekovacs



_______________________________________________
geda-user mailing list
geda-user@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user