How to use 2 blogs with the same users.

I’ve read a few topics here about to share users with two wordpress installations, but there were problems with a ‘You don’t have permission…’ message, I finally find out how you can solve this.

So, how can you have the users of wordpress installation A too on wordpress installation B:

Step 1
The two installations should be in the same database, you can do this with the prefix options.

The next steps are only for wordpress installation B:

Step 2
Find wp-settings.php, open it with a text-editor and find:

$wpdb->users          = $wpdb->prefix . 'users';

Change it to

$wpdb->users          = 'wp_users';

Find:

$wpdb->usermeta       = $wpdb->prefix . 'usermeta';

Change it to:

$wpdb->usermeta       = 'wp_usermeta';

Step 3:

Find wp-includes/capabilities.php, open it with a text-editor and find:

$this->cap_key = $wpdb->prefix . 'capabilities';

Change it to:

$this->cap_key = 'wp_capabilities';

Find all:

$this->ID, $wpdb->prefix.'user_level'

And change them to:

$this->ID, 'wp_user_level'

This steps will do the trick and you can now login on both wordpress installations with the same username and password.

I don’t know if it works with WordPress versions < 2.1

Davey