Re: [Chicken-users] Help with the mysql egg

[Jean-Philippe Theberge]

OK, I keep in mind that you can easily and succesfully modify an egg you 
had never used. 

I think this should be added to the mysql egg. I can provide a diff or 
add it myself to the egg if I am provided with a repository access.

Thanks a lot!

--
JP Theberge


Kon Lovett wrote:
> On Jan 22, 2008, at 6:42 AM, Jean-Philippe Theberge wrote:
>
> > Hi,
> >
> > I am having some trouble with the mysql egg mostly die to my 
> > misunderstanding of c-pointers
> >
> > With the egg you get data either by index or by name.  What I would 
> > like is more something like this example from the mysql-api 
> > documentation
> >
> > unsigned int num_fields;
> >
> > unsigned int i;
> > MYSQL_FIELD *fields;
> >
> > num_fields = mysql_num_fields(result);
> > fields = mysql_fetch_fields(result);
> > for(i = 0; i < num_fields; i++)
> > {
> >   printf("Field %u is %s\n", i, fields[i].name);
> > }
> >
> > The egg provide the foreign-mysql-fetch-fields. it return a 
> > #<pointer> object
> >
> > How can I extract the name from this object in scheme?  I want to do 
> > what "fields[i].name" do in the example above?
> > Thanks
>
> I have never used the mysql egg so keep that in mind.
>
> (define conn (mysql-connect ...))
>
> ;; (mysql-fetch-field-list DB) -> LIST | BOOLEAN
> ;; Returns a list of field names for the current connection result, or
> ;; #f when no result.
> (define mysql-fetch-field-list
>   (let ([get-field-name
>           (foreign-lambda* c-string ([c-pointer fields] 
> [unsigned-integer idx])
>            "return (((MYSQL_FIELD *)fields)[idx].name);")])
>     (lambda (conn)
>       (and-let* ([res (mysql-connection-result conn)])
>         (let ([fields (foreign-mysql-fetch-fields res)])
>           (let loop ([count (foreign-mysql-num-fields res)] [names '()])
>             (if (zero? count)
>                 names
>                 (let ([nxtcnt (sub1 count)])
>                   (loop nxtcnt (cons (get-field-name fields nxtcnt) 
> names)) ) ) ) ) ) ) ) )
>
> HTH
>
> > --
> >
> >
> >
> > BuddyPilots <http://www.buddypilots.com>
> > *Jean-Philippe Théberge*
> > *Programmeur Architecte*
> > Tel: (514) 353-2307
> >
> >
> >
> >
> >
> > _______________________________________________
> > Chicken-users mailing list
> > address@hidden
> > http://lists.nongnu.org/mailman/listinfo/chicken-users
>
> Best Wishes,
> Kon


--
BuddyPilots <http://www.buddypilots.com>
*Jean-Philippe Théberge*
*Programmeur Architecte*
Tel: (514) 353-2307