drop table if exists city; CREATE TABLE `city` ( `id` varchar(70) NOT NULL, `province_id` int(15) DEFAULT NULL, `city_name` varchar(90) DEFAULT NULL, `description` varchar(90) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin; load stats "s/explain_union_scan.json"; insert into city values("06766b3ef41d484d8878606393f1ed0b", 88, "chongqing", "chongqing city"); begin; update city set province_id = 77 where id="06766b3ef41d484d8878606393f1ed0b"; explain select t1.*, t2.province_id as provinceID, t2.city_name as cityName, t3.description as description from city t1 inner join city t2 on t1.id = t2.id left join city t3 on t1.province_id = t3.province_id where t1.province_id > 1 and t1.province_id < 100 limit 10; commit;