wp_set_wpdb_vars()

function wp_set_wpdb_vars() {
	global $wpdb, $table_prefix;
	if ( !empty( $wpdb->error ) )
		dead_db();

	$wpdb->field_types = array( 'post_author' => '%d', 'post_parent' => '%d', 'menu_order' => '%d', 'term_id' => '%d', 'term_group' => '%d', 'term_taxonomy_id' => '%d',
		'parent' => '%d', 'count' => '%d','object_id' => '%d', 'term_order' => '%d', 'ID' => '%d', 'comment_ID' => '%d', 'comment_post_ID' => '%d', 'comment_parent' => '%d',
		'user_id' => '%d', 'link_id' => '%d', 'link_owner' => '%d', 'link_rating' => '%d', 'option_id' => '%d', 'blog_id' => '%d', 'meta_id' => '%d', 'post_id' => '%d',
		'user_status' => '%d', 'umeta_id' => '%d', 'comment_karma' => '%d', 'comment_count' => '%d',
		// multisite:
		'active' => '%d', 'cat_id' => '%d', 'deleted' => '%d', 'lang_id' => '%d', 'mature' => '%d', 'public' => '%d', 'site_id' => '%d', 'spam' => '%d',
	);

	$prefix = $wpdb->set_prefix( $table_prefix );

	if ( is_wp_error( $prefix ) ) {
		wp_load_translations_early();
		wp_die(
			/* translators: 1: $table_prefix 2: wp-config.php */
			sprintf( __( '<strong>ERROR</strong>: %1$s in %2$s can only contain numbers, letters, and underscores.' ),
				'<code>$table_prefix</code>',
				'<code>wp-config.php</code>'
			)
		);
	}
}