From: Michael Neumann <mneumann@...>
Date: 2005-04-02T21:49:59+09:00
Subject: Re: gems for DBI and MySQL?

Am Samstag 02 April 2005 05:21 schrieb R. Mark Volkmann:
> Quoting Kirk Haines <khaines@enigo.com>:
> > R. Mark Volkmann wrote:
> > > Does Rails use DBI to access databases?
> >
> > No.
> >
> > > Does Rails support MySQL out of the box?
> > > I'm not writing a web app.  However, if the answer to both questions
> > > above is "yes" then it would seem that the easiest way to get myself
> > > setup to use MySQL
> > > would be to install Rails.  True?
> >
> > No.
> >
> > It's easy to just do it by hand.
> >
> > Get mysql-ruby (http://tmtm.org/en/mysql/ruby/README.html), which is the
> > C interface, or ruby-mysql
> > (http://tmtm.org/en/ruby/mysql/README_en.html), which is the pure Ruby
> > interface.  Follow the easy instructions to build this.
> >
> > Download DBI (http://rubyforge.org/projects/ruby-dbi).
> >
> > After unpacking ruby-dbi:
> >
> >    ruby setup.rb config --with=dbi,dbd_mysql
> >    ruby setup.rb setup
> >    ruby setup.rb install
>
> This last step is a problem when you've installed Ruby using the one-click
> installer because it tries to overwrite existing .rb files.  I had to
> delete the existing ones to get this to work.

Or you simply remove the "dbi" from the --with option:

  ruby setup.rb config --with=dbd_mysql

> > You'll be good to go.
>
> When I run my code that contains
>
>   dbh = DBI.connect('dbi:Mysql:music:localhost', 'root', '')
>
> I get
>
> c:/Ruby/Ruby1.8.2-14/lib/ruby/site_ruby/1.8/dbi/dbi.rb:490:in
> `load_driver':  is not a class/module (TypeError)
>         from c:/Ruby/Ruby1.8.2-14/lib/ruby/site_ruby/1.8/dbi/dbi.rb:392:in
> `_get _full_driver'
>         from c:/Ruby/Ruby1.8.2-14/lib/ruby/site_ruby/1.8/dbi/dbi.rb:372:in
> `connect'

You don't have the ruby-mysql or mysql-ruby library installed, do you?

> I looked at the code.  I think it's complaining about not being able to
> find a class called DBI::DriverHandle.  That class is defined in dbi.rb.
>
> Any idea what's going on here?

I think, it loads the DBD, but the first (or one of the first) lines of the 
DBD/Mysql/Mysql.rb file fails, as this loads the "mysql" library, which is 
probably not installed.

Regards,

  Michael