• mybatis-plus依赖导入
<dependency>            <groupId>com.baomidou</groupId>            <artifactId>mybatis-plus-boot-starter</artifactId>            <version>3.3.2</version>        </dependency>

倡议应用3.3.0后的版本。
导入mybatis-plus就不必导入mybatis了，抵触！

  • 连贯数据库
spring.datasource.username=rootspring.datasource.password=19981204spring.datasource.url=jdbc:mysql://localhost:3306/mybatis_plus?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8spring.datasource.driver-class-name=com.mysql.cj.jdbc.Drivermybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl//配置默认日志
  • 设置主键自增
@Data@AllArgsConstructor@NoArgsConstructorpublic class User {    @TableId(type = IdType.AUTO)    private Long id;    private String name;    private Integer age;    private String email;   }

应用注解 @TableId(type=IdType.AUTO),同时将数据库中的id字段设置为自增即可。

  • 编写配置类来进行主动注入工夫（继承元数据类并重写它的insertFill和updateFill办法）
    应用注解@TableFiled(fill=FieldFill.INSERT)
@Data@AllArgsConstructor@NoArgsConstructorpublic class User {    @TableId(type = IdType.AUTO)    private Long id;    private String name;    private Integer age;    private String email;    @TableField(fill = FieldFill.INSERT)    private LocalDateTime createTime;    @TableField(fill = FieldFill.INSERT_UPDATE)    private LocalDateTime updateTime;}
package com.ls.handler;        import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;        import org.apache.ibatis.reflection.MetaObject;        import org.springframework.stereotype.Component;        import java.time.LocalDateTime;/** * @author dell */@Componentpublic class MyMetaObjectHandler implements MetaObjectHandler {    @Override    public void insertFill(MetaObject metaObject) {        this.strictInsertFill(metaObject,"createTime", LocalDateTime.class,LocalDateTime.now());        this.strictUpdateFill(metaObject,"updateTime",LocalDateTime.class,LocalDateTime.now());    }    @Override    public void updateFill(MetaObject metaObject) {        this.strictUpdateFill(metaObject,"updateTime",LocalDateTime.class,LocalDateTime.now());    }}