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MySQL去重保留最大的那条记录（取最新的记录）
发布时间:2021-05-22以用户登录日志表为例，取用户最近登录的设备
1 SET NAMES utf8mb4; 2 SET FOREIGN_KEY_CHECKS = 0; 3 4 -- ---------------------------- 5 -- Table structure for t_login_log 6 -- ---------------------------- 7 DROP TABLE IF EXISTS `t_login_log`; 8 CREATE TABLE `t_login_log` ( 9 `id` int(11) NOT NULL AUTO_INCREMENT, 10 `user_id` int(11) NOT NULL COMMENT '用户ID', 11 `device_name` varchar(32) COLLATE utf8mb4_bin NOT NULL COMMENT '登录设备', 12 `login_time` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '登录时间', 13 PRIMARY KEY (`id`) 14 ) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin; 15 16 -- ---------------------------- 17 -- Records of t_login_log 18 -- ---------------------------- 19 BEGIN; 20 INSERT INTO `t_login_log` VALUES (1, 1121, 'iPhone 6s', '2019-07-01 19:20:25'); 21 INSERT INTO `t_login_log` VALUES (2, 2120, 'vivo x20', '2019-06-28 16:21:11'); 22 INSERT INTO `t_login_log` VALUES (3, 1607, 'huawei P30', '2019-07-04 19:21:59'); 23 INSERT INTO `t_login_log` VALUES (4, 2120, 'vivo x20', '2019-06-30 19:22:34'); 24 INSERT INTO `t_login_log` VALUES (5, 2120, 'vivo x20', '2019-07-04 19:23:07'); 25 INSERT INTO `t_login_log` VALUES (6, 1121, 'iPad mini', '2019-07-03 19:23:25'); 26 INSERT INTO `t_login_log` VALUES (7, 1607, 'iPhone 8 Plus', '2019-06-30 19:24:06'); 27 INSERT INTO `t_login_log` VALUES (8, 1970, 'MI8', '2019-07-03 19:25:00'); 28 COMMIT; 29 30 SET FOREIGN_KEY_CHECKS = 1;