Wordpress selecting wrong DB

I have a Wordpress site that uses two databases -- one section queries one database ("database_A"), and开发者_如何学Go then Wordpress makes its connection to its own database ("database_B").

Everything it working well until I go to call this function:

$pageposts = $wpdb->get_results($querystr, OBJECT);

The Wordpress suddenly selects the wrong database ("database_A") when it was just using ("database_B").

How do I (a) prevent it from selecting ("database_A") or (b) make a call to have it select ("database_B")?

The wpdb class in WP ha a select() method. You should just be able to call it directly.

$wpdb->select('database_B');

You could also instantiate a second object that uses database_b:

$wpdb_b = new wpdb($db_b_user, $db_b_pwd, 'database_B', $db_b_host);

You can create a new $wpdb-var, like this:

<?php
$wpdb2 = new wpdb($user, $dbpassword, $db2, $dbhost);
?>

Now you can easily select items from the other database:

<?php
$pageposts = $wpdb2->get_results($querystr, OBJECT);
?>

I hope it helps you :]

(edit: Are you sure it suddenly changes the database? I mean, is it using database A before it is using database B, that's almost impossible...)