Mybatis xxxMapper.xml 三表关联，配置文件

VideoMapper.xml#

<?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="net.ybclass.online_ybclass.mapper.VideoMapper">
    <resultMap id="videoDetailResultMap" type="Video">
        <id column="id" jdbcType="INTEGER" property="id"/>
        <result column="title" jdbcType="VARCHAR" property="title"/>
        <result column="summary" jdbcType="VARCHAR" property="summary"/>
        <result column="cover_img" jdbcType="VARCHAR" property="coverImg"/>
        <result column="price" jdbcType="INTEGER" property="price"/>
        <result column="point" jdbcType="DOUBLE" property="point"/>
        <result column="create_time" jdbcType="TIMESTAMP" property="createTime"/>
        <collection property="chapterList" ofType="Chapter">
            <id column="chapter_id" jdbcType="INTEGER" property="id"/>
            <result column="chapter_title" jdbcType="VARCHAR" property="title"/>
            <result column="ordered" jdbcType="INTEGER" property="ordered"/>
            <result column="chapter_create_time" jdbcType="TIMESTAMP" property="createTime"/>
            <collection property="episodeList" ofType="Episode">
                <id column="episode_id" jdbcType="INTEGER" property="id"/>
                <result column="episode_title" jdbcType="VARCHAR" property="title"/>
                <result column="num" jdbcType="INTEGER" property="num"/>
                <result column="episode_ordered" jdbcType="INTEGER" property="ordered"/>
                <result column="chapter_id" jdbcType="INTEGER" property="chapterId"/>
                <result column="video_id" jdbcType="INTEGER" property="videoId"/>
                <result column="play_url" jdbcType="VARCHAR" property="playUrl"/>
                <result column="free" jdbcType="INTEGER" property="free"/>
                <result column="play_create_time" jdbcType="TIMESTAMP" property="createTime"/>
            </collection>
        </collection>
    </resultMap>
    <select id="findDetailById" resultMap="videoDetailResultMap">
        SELECT v.id,v.title,v.summary,v.cover_img,v.price,v.create_time,v.point,
c.id chapter_id,c.video_id,c.title chapter_title,c.ordered,c.create_time chapter_create_time,
e.id episode_id,e.num,e.chapter_id,e.video_id,e.title episode_title,e.ordered episode_ordered,e.play_url,e.free,e.create_time play_create_time
FROM video v
LEFT JOIN chapter c ON v.id=c.video_id
LEFT JOIN episode e ON c.id=e.chapter_id
WHERE v.id=#{video_id}
ORDER BY c.ordered,e.num ASC
    </select>
</mapper>

Video.java#

package net.ybclass.online_ybclass.domain;

import java.util.Date;
import java.util.List;

/**
 * 视频对象
 */
public class Video {
    private Integer id;
    private String title;
    private String summary;
    private String coverImg;
    private Integer price;
    private Date createTime;
    private Double point;
    private List<Chapter> chapterList;

    public List<Chapter> getChapterList() {
        return chapterList;
    }

    public void setChapterList(List<Chapter> chapterList) {
        this.chapterList = chapterList;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getSummary() {
        return summary;
    }

    public void setSummary(String summary) {
        this.summary = summary;
    }

    public String getConverImg() {
        return coverImg;
    }

    public void setConverImg(String converImg) {
        this.coverImg = converImg;
    }

    public Integer getPrice() {
        return price;
    }

    public void setPrice(Integer price) {
        this.price = price;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    public Double getPoint() {
        return point;
    }

    public void setPoint(Double point) {
        this.point = point;
    }

    @Override
    public String toString() {
        return "Video{" +
                "id=" + id +
                ", title='" + title + '\'' +
                ", summary='" + summary + '\'' +
                ", converImg='" + coverImg + '\'' +
                ", price=" + price +
                ", createTime=" + createTime +
                ", point=" + point +
                ", chapterList=" + chapterList +
                '}';
    }
}

Chapter.java#

package net.ybclass.online_ybclass.domain;

import java.util.Date;
import java.util.List;

/**
 * 章
 */
public class Chapter {
    private Integer id;
    private Integer videoId;
    private String title;
    private Integer ordered;
    private Date createTime;
    private List<Episode> episodeList;

    public List<Episode> getEpisodeList() {
        return episodeList;
    }

    public void setEpisodeList(List<Episode> episodeList) {
        this.episodeList = episodeList;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public Integer getVideoId() {
        return videoId;
    }

    public void setVideoId(Integer videoId) {
        this.videoId = videoId;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public Integer getOrdered() {
        return ordered;
    }

    public void setOrdered(Integer ordered) {
        this.ordered = ordered;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    @Override
    public String toString() {
        return "Chapter{" +
                "id=" + id +
                ", videoId=" + videoId +
                ", title='" + title + '\'' +
                ", ordered=" + ordered +
                ", createTime=" + createTime +
                ", episodeList=" + episodeList +
                '}';
    }
}

Episode.java#

package net.ybclass.online_ybclass.domain;

import java.util.Date;
import java.util.List;

/**
 * 集
 */
public class Episode {
    private Integer id;
    private String title;
    private Integer num;
    private Integer ordered;
    private String playUrl;
    private Integer chapterId;
    private Integer free;
    private Integer videoId;
    private Date createTime;
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public Integer getNum() {
        return num;
    }

    public void setNum(Integer num) {
        this.num = num;
    }

    public Integer getOrdered() {
        return ordered;
    }

    public void setOrdered(Integer ordered) {
        this.ordered = ordered;
    }

    public String getPlayUrl() {
        return playUrl;
    }

    public void setPlayUrl(String playUrl) {
        this.playUrl = playUrl;
    }

    public Integer getChapterId() {
        return chapterId;
    }

    public void setChapterId(Integer chapterId) {
        this.chapterId = chapterId;
    }

    public Integer getFree() {
        return free;
    }

    public void setFree(Integer free) {
        this.free = free;
    }

    public Integer getVideoId() {
        return videoId;
    }

    public void setVideoId(Integer videoId) {
        this.videoId = videoId;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    @Override
    public String toString() {
        return "Episode{" +
                "id=" + id +
                ", title='" + title + '\'' +
                ", num=" + num +
                ", ordered=" + ordered +
                ", playUrl='" + playUrl + '\'' +
                ", chapterId=" + chapterId +
                ", free=" + free +
                ", videoId=" + videoId +
                ", createTime=" + createTime +
                '}';
    }
}

表结构#