-ALTER TABLE account_auth_openid MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE account_lost_passwords MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE account_profiles MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE aliases MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE announce_read MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE announces MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE axletter_ins MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE axletter_rights MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE carvas MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE contacts MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE email_list_moderate MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE email_options MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE email_send_save MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE email_watch MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE emails MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE forum_innd MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE forum_profiles MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE forum_subs MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE group_announces MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE group_announces_read MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE group_event_participants MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE group_member_sub_requests MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE group_members MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE homonyms MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE ip_watch MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE log_last_sessions MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE log_sessions MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE newsletter_ins MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE payment_transactions MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE profile_modifications MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE register_marketing MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE register_mstats MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE register_pending MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE register_subs MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE reminder MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE requests MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE requests_hidden MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE watch MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE watch_nonins MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
-ALTER TABLE watch_promo MODIFY COLUMN uid INT(11) UNSIGNED NOT NULL DEFAULT 0;
+ALTER TABLE account_auth_openid MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE account_lost_passwords MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE account_profiles MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE aliases MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE announce_read MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE announces MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE axletter_ins MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE axletter_rights MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE carvas MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE contacts MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE email_list_moderate MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE email_options MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE email_send_save MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE email_watch MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE emails MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE forum_innd MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE forum_profiles MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE forum_subs MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE group_announces MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE group_announces_read MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE group_event_participants MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE group_member_sub_requests MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE group_members MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE homonyms MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE ip_watch MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE log_last_sessions MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE log_sessions MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE newsletter_ins MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE payment_transactions MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE profile_modifications MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE register_marketing MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE register_mstats MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE register_pending MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE register_subs MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE reminder MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE requests MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE requests_hidden MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE watch MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE watch_nonins MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;
+ALTER TABLE watch_promo MODIFY COLUMN uid INT(11) UNSIGNED DEFAULT NULL;