Read table from another database - sql-server

Question

Is it possible to read tables from another database using the builting CakePHP model features? I don't mean having an entirely different configuration in DATABASE_CONFIG but using the same host, user and password. The obvious thing:
class Provincia extends AppModel {
public $useTable = 'shared_data.dbo.provincia';
}
class DebugController extends AppController {
public function index() {
/* #var $modeloProvincia Provincia */
$modeloProvincia = ClassRegistry::init('Provincia');
$provincias = $modeloProvincia->find('all');
}
}
... triggers:
Error: Table shared_data.dbo.provincia for model Provincia was not found in datasource default.

Answer 1

I'll share my findings so far...
Short answer: you cannot.
CakePHP magic depends heavily on information about tables and columns fetched from the INFORMATION_SCHEMA views. That information is gathered in \Sqlserver::listSources (list of tables) and \Sqlserver::describe (list of columns).
While it's possible to extend the datasource driver and reimplement these methods:
// Model/Datasource/CustomSqlserver.php
class CustomSqlserver extends Sqlserver {
}
class DATABASE_CONFIG {
public $default = array(
'datasource' => 'CustomSqlserver',
// ...
);
}
... that's just the tip of the iceberg. The data structures account for two levels:
Schema (e.g. dbo)
Table (e.g. users)
They aren't designed for an extra database level on top. As a result, you end up needing to patch so much code that it isn't worth the effort.
I've also been playing with Synonyms in SQL Server. It's a more promising path because, while you still need to write \CustomSqlserver::listSources and \CustomSqlserver::describe yourself, to most (not all) effects they behave like regular tables. The main restriction though is that there can't be duplicate table names.

Answer 2

You would need to add a new connection to DATABASE_CONFIG, but you could do this in the constructor so that you can inherit your default database credentials and just modify the database name:-
public function __construct() {
$this->alt = $this->default;
$this->alt['database'] = 'provincia';
}
Then in your Provincia model you can swap to the alt database connection:-
public function __construct($id = false, $table = null, $ds = null) {
parent::__construct($id, $table, $ds);
$this->useDbConfig = 'alt';
}