Re: [Dancer-users] D::P::Database: Changing Databases dynamically between routes

27 Jan 2012


      Thanks David.  Responses embedded....


On Fri, Jan 27, 2012 at 5:15 PM, David Precious <davidp@preshweb.co.uk>wrote:
...
On Fri, 27 Jan 2012 14:40:46 +0530
Gurunandan Bhat <gbhat@pobox.com> wrote:
...
Hi,
I am trying to use Dance::Plugin::Database with SQLite in a situation
where different databases must be connected to in different routes.
For example:
get route_1 => sub {
my $dbfile_1 = "...";
    my $dbh = database({
        driver: 'SQLite',
        database => $dbfile_1,
        .... Other Options
    });
... Work with $dbh
}
[...]
My Config file contains:
plugins:
  Database:
    driver: 'SQLite'
Since I dont know what the database is going to be I dont have the
database setting here (probably incorrect, but I dont know any better)
Well, by providing a hashref of settings to the database() keyword,
you're overriding anything in the config file anyway.
...
Can't connect to data source 'dbi:SQLite' because I can't work out
what driver to use (it doesn't seem to contain a 'dbi:driver:' prefix
and the DBI_DRIVER env var is not set) at
/home/nandan/perl5/perlbrew/perls/perl-5.14.2/lib/site_perl/5.14.2/Dancer/Plugin/Database.pm
...
line 163
Have you accidentally called database() with no params at some point?
That would cause that error, as it would then use the details in the
config file, which don't contain the database name (which is of course
required for the SQLite driver, so it knows what file to look at...)
I dont think so. Let me look more deeply into what exactly is happening. As
I said the first few calls (routes) succeed. It begins to fail after the
third route.
...
...
Could you suggest the correct way to set the database dynamically in
each route?
You've seen Dancer::Plugin::Database's support for multiple named
connection settings, yes/
I am aware of the named connections. Unfortunately, the functionality
required is for users to upload an SQLite file and browse the uploaded
files as well as previously uploaded files. So not only dont I know which
database the user connects to, I am also not aware of how many there are.In
this situation, I believe using name connections in this situation is not
possible?
...
https://metacpan.org/module/Dancer::Plugin::Database#DEFINING-MULTIPLE-CONNE...
I would configure each database in the config file, as e.g.:
plugins:
         Database:
             connections:
                 foo:
                     driver: 'SQLite'
                     database: 'foo.sqlite'
                 bar:
                     driver: 'SQLite'
                     database: 'bar.sqlite'
... etc.
Then, in your code, you can just say database('foo') to get a DB handle
configured to talk to the 'foo' database, and database('bar') to talk
to the 'bar' database.
I think that would be far cleaner, and keeps the configuration details
of which database to talk to out of your code, which is definitely a
bonus - config belongs in the config file, not in the code :)
Cheers
Dave P
--
David Precious ("bigpresh") <davidp@preshweb.co.uk>
http://www.preshweb.co.uk/     www.preshweb.co.uk/twitter
www.preshweb.co.uk/linkedin    www.preshweb.co.uk/facebook
www.preshweb.co.uk/cpan        www.preshweb.co.uk/github
_______________________________________________
Dancer-users mailing list
Dancer-users@perldancer.org
http://www.backup-manager.org/cgi-bin/listinfo/dancer-users