CREATE TABLE `login` ( `id` int(4) NOT NULL, `user_id` int(4) NOT NULL, `client_id` int(4) NOT NULL, `date` date NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; INSERT INTO `login` VALUES (1,2,1,'2020-10-12'),(2,3,2,'2020-10-12'),(3,1,2,'2020-10-12'),(4,2,2,'2020-10-13'),(5,1,2,'2020-10-13'),(6,5,2,'2020-10-13'),(7,3,1,'2020-10-14'),(8,4,1,'2020-10-14'),(9,5,1,'2020-10-14'),(10,1,1,'2020-10-14'),(11,4,1,'2020-10-15'); 试下这组数据，第二天留存率是2.sql有问题