只含街道 没前3级 `id` char(12) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '记录唯一标识（地区编码，顶级编码为-1）', `parent_id` char(12) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '父标志,根节点的值为0', `name` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '地区名称',