WordPress MU

Well i have installed WordPress MU, using Apache2, PHP 5.2
my site developed with php5.2 and symphony.
I have set the WordPress at the root directory of my site web directory inder blogs/
this is working fine, i can see blogs, and create new one.
When i try to call the blog login page from my symfuny project, i get error.
i have puten all the wordpress code from the installation in my \frontend\modules\user\templates and call wp-loginSuccess from my action.
the problem i have is that the $wpdb gets error when trying to call it -
Call to a member function get_var() on a non-object

for some reason this global db connection is not initiated,
someone knows where this initiation takes place? and way it is not working?

maybe because at initiating the wordpress DB i specified the directory of : web\blogs
and now i moved all the code to my module at :
\frontend\modules\user\templates

could someone help please.

Including ~/wp-includes/wpdb.php (where ~ is the root directory of WordPress) should give you the initialized variable, $wbdb, then declare the global in any functions that need it.

Having not used symfony, if that doesn't help, posting the problem code might help in solving the issue.

something like this may be in order:

<?php

if (empty($wp)) {
require_once('/blog/wp-config.php');
wp();
}
?>