废话不多说，直接上！！！！

先准备两个实体类

第一个

订单详细实体类

TbOrderEntity

/**
     * 用户ID
     */
	private Long userid;
    /**
     * 商品ID
     */
	private Long goodsId;
    /**
     * 商店ID
     */
	private Long shopid;
    /**
     * 店铺名称
     */
	private String shopname;
    /**
     * 商品购买数量
     */
	private Integer goodsBuynum;
    /**
     * 商品图片地址
     */
	private String goodsImg;
    /**
     * 商品名称
     */
	private String goodsName;
    /**
     * 商品价格
     */
	private BigDecimal goodsPrice;
    /**
     * 地址
     */
	private String address;
    /**
     * 下单日期
     */
	private Date orderdate;
    /**
     * 订单号
     */
	private Long ordernumber;
    /**
     * 付款状态
     */
	private Integer status;
    /**
     * 修改者
     */
	private String regenerator;
    /**
     * 修改时间
     */
	private Date updateTime;
    /**
     * 租户编码
     */
	private Long tenantCode;
    /**
     * 备注
     */
	private String remark;

第二个

TEntity

/**
     * 商家idname
     */
	private String shopid;

    /**
     * 商家名称
     */
    private String shopname;
    /**
     * 用户id
     */
	private Long userid;
    /**
     * 商品id
     */
    private Long goodsid;
    /**
     * 商品信息
     */
	private List<TbOrderEntity> orderEntities;
    /**
     * 备注
     */
	private String remark;
    /**
     * 创建者
     */
    private Long creator;
    /**
     * 创建时间
     */
    private Date createDate;
    /**
     * 修改者
     */
	private String regenerator;
    /**
     * 修改时间
     */
	private Date updateDate;
    /**
     * 租户编码
     */
	private Long tenantCode;

后面是控制层（controller）

TbOrderController

@Autowired
    private TbOrderService tbOrderService;
    @GetMapping("/uid/{uid}")
    @ApiOperation("根据客户Id信息")
    public Result<List<TEntity>> queryuid(@PathVariable("uid") Long uid){
        List<TEntity> data = tbOrderService.query(uid);

        return new Result<List<TEntity>>().ok(data);
    }

这里就写一个查询方法。。。。。

服务层接口（service）

TbOrderService

List<TEntity> query(Long uid);

服务类

TbOrderServiceImpl

//根据uid搜索
    @Override
    public List<TEntity> query(Long uid) {
        List<TEntity> entity = tbOrderDao.selectuid(uid);

        return ConvertUtils.sourceToTarget(entity, TEntity.class);
    }

Dao层

TbOrderDao

List<TEntity> selectuid(Long uid);

Mapper层

最关键的地方就在这！！！！！

<resultMap type="com.zx.entity.TEntity" id="TbCartMap">
        <id column="shopid" property="shopid"/>
        <result column="shopname" property="shopname"/>
        <collection property="orderEntities" ofType="com.zx.entity.TbOrderEntity">
            <result property="id" column="id"/>
            <result property="userid" column="userid"/>
            <result property="goodsId" column="goods_id"/>
            <result property="shopid" column="shopId"/>
            <result property="shopname" column="shopName"/>
            <result property="goodsBuynum" column="goods_buynum"/>
            <result property="goodsImg" column="goods_img"/>
            <result property="goodsName" column="goods_name"/>
            <result property="goodsPrice" column="goods_price"/>
            <result property="address" column="address"/>
            <result property="orderdate" column="orderDate"/>
            <result property="ordernumber" column="orderNumber"/>
            <result property="status" column="status"/>
            <result property="creator" column="creator"/>
            <result property="createDate" column="create_date"/>
            <result property="regenerator" column="regenerator"/>
            <result property="updateTime" column="update_time"/>
            <result property="tenantCode" column="tenant_code"/>
            <result property="remark" column="remark"/>
        </collection>
    </resultMap>
    <select id="selectuid" parameterType="Long" resultMap="TbCartMap">
    select
        tr.id,
        tr.shopId,
        tr.goods_id,
        tr.shopName,
        tr.goods_buynum,
        tr.goods_img,
        tr.goods_name,
        tr.goods_price,
        tr.address,
        tr.orderDate,
        tr.orderNumber,
        tr.status
    from tb_order tr
    where tr.userid=#{userid}
    order by tr.goods_id
</select>

查询结果：

{
  "code": 0,
  "msg": "success",
  "data": [
    {
      "id": null,
      "creator": null,
      "createDate": null,
      "tenantCode": null,
      "shopid": "1",
      "shopname": "雨润超市",
      "userid": null,
      "goodsid": null,
      "orderEntities": [
        {
          "id": "1",
          "creator": null,
          "createDate": null,
          "tenantCode": null,
          "userid": null,
          "goodsId": "1",
          "shopid": "1",
          "shopname": "雨润超市",
          "goodsBuynum": 111,
          "goodsImg": "http",
          "goodsName": "敌敌畏",
          "goodsPrice": 1000,
          "address": "江苏",
          "orderdate": "2019-11-28 15:26:11",
          "ordernumber": "1",
          "status": 1,
          "regenerator": null,
          "updateTime": null,
          "remark": null
        },
        {
          "id": "5",
          "creator": null,
          "createDate": null,
          "tenantCode": null,
          "userid": null,
          "goodsId": "3",
          "shopid": "1",
          "shopname": "雨润超市",
          "goodsBuynum": 111,
          "goodsImg": "",
          "goodsName": null,
          "goodsPrice": null,
          "address": null,
          "orderdate": null,
          "ordernumber": null,
          "status": null,
          "regenerator": null,
          "updateTime": null,
          "remark": null
        }
      ],
      "remark": null,
      "regenerator": null,
      "updateDate": null
    },
    {
      "id": null,
      "creator": null,
      "createDate": null,
      "tenantCode": null,
      "shopid": "2",
      "shopname": "苏果超市",
      "userid": null,
      "goodsid": null,
      "orderEntities": [
        {
          "id": "4",
          "creator": null,
          "createDate": null,
          "tenantCode": null,
          "userid": null,
          "goodsId": "2",
          "shopid": "2",
          "shopname": "苏果超市",
          "goodsBuynum": 222,
          "goodsImg": "http",
          "goodsName": "化肥",
          "goodsPrice": 3000,
          "address": "河南",
          "orderdate": "2019-11-29 16:14:29",
          "ordernumber": "1",
          "status": 1,
          "regenerator": null,
          "updateTime": null,
          "remark": null
        }
      ],
      "remark": null,
      "regenerator": null,
      "updateDate": null
    }
  ]
}