一、添加依赖

<!-- MyBatisPlus依赖-->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.5.1</version>
</dependency>
<!--LomBok依赖-->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId> <optional>true</optional>
</dependency>
<!--mysql依赖-->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>

二、配置数据源

spring:
    # 配置数据源信息 
    datasource:
        # 配置数据源类型
        type: com.zaxxer.hikari.HikariDataSource
        # 配置连接数据库信息
        driver-class-name: com.mysql.cj.jdbc.Driver
        url: jdbc:mysql://localhost:3306/mybatis_plus?characterEncoding=utf-8&useSSL=false
        username: root
        password: 123456

三、在启动类上扫描dao的路径

四、创建实体并与数据库表关联

package demo.entity;

import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data //生成Get和Set方法，重写toString
@AllArgsConstructor //生成有参构造器
@NoArgsConstructor //生成无参构造器
@TableName("t_user") //设置表名
public class User {
    @TableId //指定主键id
    private Long id;

    private String userName;
    private String passwd;
}

五、创建dao继承自BaseMapper

package demo.dao;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import demo.entity.User;

public interface UserDAO extends BaseMapper<User> {

}

六、在controller中测试

第1步：通过AutoWired注解实例化dao对象

第2步：调用dao方法实现增删改查

@RequestMapping("/t2")
public int insertUser(){
    int count = dao.insert(new User(null, "tom", "123"));
    return count;
}

运行效果