mysql去重查询只留一条最新的记录

需求：mysql去重查询只保留一条最新的记录

表结构与初始数据如下SQL文件：

-- MySQL dump 10.13  Distrib 8.0.28, for Linux (x86_64)
--
-- Host: localhost    Database: test01
-- ------------------------------------------------------
-- Server version	8.0.28-0ubuntu0.20.04.3

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!50503 SET NAMES utf8 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

--
-- Table structure for table `MyClass`
--

DROP TABLE IF EXISTS `MyClass`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!50503 SET character_set_client = utf8mb4 */;
CREATE TABLE `MyClass` (
  `id` int NOT NULL AUTO_INCREMENT,
  `name` char(20) NOT NULL,
  `sex` int NOT NULL DEFAULT '0',
  `degree` double(16,2) DEFAULT NULL,
  `inserttime` text,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
/*!40101 SET character_set_client = @saved_cs_client */;

--
-- Dumping data for table `MyClass`
--

LOCK TABLES `MyClass` WRITE;
/*!40000 ALTER TABLE `MyClass` DISABLE KEYS */;
INSERT INTO `MyClass` VALUES (1,'Tom',0,96.45,'2022-02-19 18:00:00'),(2,'Joan',0,82.99,'2022-02-19 18:20:00'),(3,'Wang',0,96.59,'2022-02-19 18:30:00'),(4,'Tom',0,96.45,'2022-02-19 17:00:00'),(5,'Joan',0,82.99,'2022-02-19 18:25:00'),(6,'Wang',0,96.59,'2022-02-19 18:35:00');
/*!40000 ALTER TABLE `MyClass` ENABLE KEYS */;
UNLOCK TABLES;
/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

-- Dump completed on 2022-02-20  4:35:15

SQL统计语句：

#全表扫描查询
SELECT * FROM test01.MyClass;
#根据name去重统计查询最新数据
SELECT * FROM test01.MyClass
WHERE name in (SELECT name FROM test01.MyClass 
GROUP BY name)
AND inserttime in (SELECT max(inserttime) FROM test01.MyClass 
GROUP BY name)

全表扫描查询_结果：

根据name去重统计查询最新数据_结果：