-`id` bigint(20) NOT NULL auto_increment,
-`userid` bigint(20) NOT NULL DEFAULT 0,
-`level` smallint(6) NOT NULL DEFAULT 0,
-`refid` bigint(20) NOT NULL DEFAULT 0,
+`id` BIGINT(20) UNSIGNED NOT NULL auto_increment,
+`userid` BIGINT(20) UNSIGNED NOT NULL DEFAULT 0,
+`level` smallINT(6) UNSIGNED NOT NULL DEFAULT 0,
+`refid` BIGINT(20) UNSIGNED NOT NULL DEFAULT 0,