[Catalyst] getting database handles and run arbitrary SQL

[Tomas Doran]

On 24 Sep 2008, at 08:37, Johannes Plunien wrote:
> On 24.09.2008, at 09:15, theshz wrote:
>
>> Is it possible to get the database handle and run SQL directly as  
>> in DBI?
>
> yes, try:
>
> my $dbh = $c->model('DBIC::User')->result_source->storage->dbh;

However - please note that doing this in your Controller is _not_ a  
recommended application pattern.

If you do that, you will swiftly have domain logic in your  
controllers, and any useful testing you can do will be forced to be  
system testing with WWW::Mechanize. (There is nothing to test in the  
model, and mocking the whole of Catalyst + Model to test is just too  
much).

I highly recommend that you implement your domain logic in a model  
class (it doesn't matter if that is a DBIC class, or a class with  
methods that work on a $dbh - see Catalyst::Model::DBI, or anything  
else).

Then your controller code becomes a case of marshaling some request  
parameters, throwing them into your model and stashing the resultant  
data structures produced by the model. Controller means that it  
controls the other objects actions, *not* that it does the heavy  
lifting itself.

You can then reuse your domain logic outside of Catalyst and test it  
in isolation (and trivially write command line scripts which also  
interact with the model), and the controllers are simple enough that  
testing them using mock objects is doable.

Cheers
t0m