一
在pom.xml文件中添加依赖（这里就不详细叙述了，可以百度）。
二
在启动类中通过@MapperScan注解配置扫描mapper接口

package com.syc;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import tk.mybatis.spring.annotation.MapperScan;

@SpringBootApplication
//通过注解配置扫描mapper接口所在包
@MapperScan(value="com.syc.mapper")
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class);
    }
}

三
在application.yml文件中添加mybatis相关配置

mybatis:
  #配置实体类别名包扫描
  type-aliases-package: com.syc.domain
  #配置mybatis中mapper接口对应xml文件所在路径
  mapper-locations: classpath*:mapperConfig/*Mapper.xml
 

四
给mapper接口添加@Mapper注解（由于我之前引用了通用mapper，所以代码中@Mapper注解为全路径），正常情况下直接添加@Mapper注解就可以

package com.syc.mapper;
import com.syc.domain.Orders;
import tk.mybatis.mapper.common.Mapper;
import java.util.List;

@org.apache.ibatis.annotations.Mapper
public interface OrdersMapper extends Mapper<Orders> {
    List<Orders> getOrderProduct();
}

五
编写OrdersMapper.xml文件

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.syc.mapper.OrdersMapper">
    <resultMap id="order_product_map" type="com.syc.domain.Orders">
        <id property="id" column="id"/>
        <result property="ordernum" column="ordernum"/>
        <result property="ordertime" column="ordertime"/>
        <result property="peoplecount" column="peoplecount"/>
        <result property="orderdesc" column="orderdesc"/>
        <result property="paytype" column="paytype"/>
        <result property="orderstatus" column="orderstatus"/>
        <result property="productid" column="productid"/>
        <!--association用于配置一对一关系 property:orders中product实体 javaType:product实体的数据类型（product对应的实体类）-->
        <association property="product" javaType="com.syc.domain.Product">
            <id property="id" column="productid"/>
            <result property="productnum" column="productnum"/>
            <result property="productname" column="productname"/>
            <result property="cityname" column="cityname"/>
            <result property="departuretime" column="departuretime"/>
            <result property="productprice" column="productprice"/>
            <result property="productdesc" column="productdesc"/>
            <result property="productstatus" column="productstatus"/>
        </association>
    </resultMap>
    <select id="getOrderProduct"  resultMap="order_product_map">
        SELECT
            o.id,
            o.ordernum,
            o.ordertime,
            o.peoplecount,
            o.orderdesc,
            o.paytype,
            o.orderstatus,
            o.productid,
            p.productnum,
            p.productname,
            p.cityname,
            p.departuretime,
            p.productprice,
            p.productdesc,
            p.productstatus
        FROM
            orders o
            LEFT JOIN product p
              ON o.productid = p.id
    </select>
</mapper>