1.ResultMap结果映射

 2.利用java对象保存保存多表关联结果

2.1  创建GoodsDTOd.java，用于对原始数据进行扩展，用于数据保存和传递（src/main/java/com/imooc/mybatis/dto）

2.2 goods.xml

2.3  测试类

 2.4 对上述案列进行扩展

2.4.1 创建entity实体类Category.java

package com.imooc.mybatis.entity;

public class Category {
    private Integer categoryId;
    private String categoryName;
    private Integer parentId;
    private Integer categoryLevel;
    private Integer categoryOrder;

    public Integer getCategoryId() {
        return categoryId;
    }

    public void setCategoryId(Integer categoryId) {
        this.categoryId = categoryId;
    }

    public String getCategoryName() {
        return categoryName;
    }

    public void setCategoryName(String categoryName) {
        this.categoryName = categoryName;
    }

    public Integer getParentId() {
        return parentId;
    }

    public void setParentId(Integer parentId) {
        this.parentId = parentId;
    }

    public Integer getCategoryLevel() {
        return categoryLevel;
    }

    public void setCategoryLevel(Integer categoryLevel) {
        this.categoryLevel = categoryLevel;
    }

    public Integer getCategoryOrder() {
        return categoryOrder;
    }

    public void setCategoryOrder(Integer categoryOrder) {
        this.categoryOrder = categoryOrder;
    }
}

2.4.2创建GoodsDTOd.java，用于对原始数据进行扩展，用于数据保存和传递（src/main/java/com/imooc/mybatis/dto）

package com.imooc.mybatis.dto;

import com.imooc.mybatis.entity.Category;
import com.imooc.mybatis.entity.Goods;

//Data Transfer Object--数据传输对象
public class GoodsDTO {
    private Goods goods = new Goods();
    private Category category = new Category();
    private String test;

    public Goods getGoods() {
        return goods;
    }

    public void setGoods(Goods goods) {
        this.goods = goods;
    }

    public Category getCategory() {
        return category;
    }

    public void setCategory(Category category) {
        this.category = category;
    }

    public String getTest() {
        return test;
    }

    public void setTest(String test) {
        this.test = test;
    }
}

2.4.3 测试类