查询对象中存在List集合 如何返回给前端

1.首先先建两个实体类 封装返回给前端的数据

package com.meishi.mall.modules.inquiry.entity.vo;

import com.meishi.mall.modules.inquiry.entity.dto.SaleInquiryDto;
import lombok.Data;

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

@Data
public class MakeInquiryVo {


    private String id;

    private String billNo;

    private Date crtTime;

    List<SaleInquiryDto> items;
}

该实体为编号对应多个数据内容

package com.meishi.mall.modules.inquiry.entity.dto;


import com.baomidou.mybatisplus.annotations.TableField;
import lombok.Data;

import java.util.Date;

@Data
public class SaleInquiryDto {


    private String qty;


    private String price;


    private String itemNo;


    private String specModel;

    private String billStatus;

    private String skuName;

    private String deliveryTime;

    private Date disabledDate;

    private String crtTime;

    private String billNo;

    private String brandName;

    private String goodsId;

    private String quotePrice;

    private String productPic;
}

2.编写对应的mybatis映射文件

    /**
     * 获取最终数据
     */
     List<MakeInquiryVo> selectInquiry(@Param("billNo") List<String> billNo,@Param("inquiryDto") InquiryDto inquiryDto);

此时注意一对多的关系（如果MakeInquiryVo显示数据非集合数据，而集合数据SaleInquiryDto也有该数据，数据重了）必须写 MakeInquiryVo对应的数据如（billNo和对应的的时间）

 <!--resultMap  -->
    <resultMap id="ResultMapInquiry" type="com.meishi.mall.modules.inquiry.entity.vo.MakeInquiryVo">
        <id column="id" property="id"/>
        <result column="billNo" property="billNo"/>
        <result column="crtTime" property="crtTime"/>
        <collection property="items" ofType="com.meishi.mall.modules.inquiry.entity.dto.SaleInquiryDto">
            <id property="qty" column="items.qty"/>
            <id property="price" column="items.price"/>
            <id property="itemNo" column="items.itemNo"/>
            <id property="billStatus" column="items.billStatus"/>
            <id property="skuName" column="items.skuName"/>
            <id property="deliveryTime" column="items.deliveryTime"/>
            <id property="disabledDate" column="items.disabledDate"/>
            <id property="brandName" column="items.brandName"/>
            <id property="goodsId" column="items.goodsId"/>
            <id property="quotePrice" column="items.quotePrice"/>
            <id property="productPic" column="items.productPic"/>
            <id property="specModel" column="items.specModel"/>
        </collection>
    </resultMap>

    <select id="selectInquiry" resultMap="ResultMapInquiry">
        SELECT
        oy.id AS id,
        oy.bill_no AS billNo,
        oy.crt_time AS crtTime,
        oy.bill_status AS "items.billStatus",
        oy.disabled_date AS "items.disabledDate",
        om.brand_name AS "items.brandName",
        om.qty AS "items.qty",
        om.quote_price AS "items.quotePrice",
        om.sku_name AS "items.skuName",
        om.item_no AS "items.itemNo",
        om.goods_id AS "items.goodsId",
        om.spec_model AS "items.specModel",
        om.delivery_time AS "items.deliveryTime",
        om.productPic AS "items.productPic"
        FROM `oms_sale_inquiry` oy
        LEFT JOIN `oms_sale_inquiry_item` om ON om.`bill_no`=oy.`bill_no`
        WHERE
        	<!-- 将得到的编号遍历存在对应实体类中-->
            oy.bill_no IN
            <foreach collection="billNo" item="item" index="index" open="(" separator="," close=")">
            #{item}
            </foreach>
            <if test="inquiryDto.customerId!=null and inquiryDto.customerId.trim()!=''">
            AND oy.customer_id = #{inquiryDto.customerId}
            </if>
            <if test="inquiryDto.billStatus!=null and inquiryDto.billStatus.trim()!=''">
            AND oy.`bill_status` = #{inquiryDto.billStatus}
            </if>
            <if test="inquiryDto.number!=null and inquiryDto.number.trim()!=''">
            AND oy.bill_no = #{inquiryDto.number}
            </if>
            <if test="inquiryDto.dateOne!=null and inquiryDto.dateOne.trim()!=''">
            AND oy.crt_time >= #{inquiryDto.dateOne}
            </if>
            <if test="inquiryDto.dateTwo!=null and inquiryDto.dateTwo.trim()!=''">
            AND oy.crt_time &lt;= #{inquiryDto.dateTwo}
            </if>
        order by oy.crt_time DESC
    </select>

编写对应的service层以及实现类

 Map<String, Object> selectPageALLItem(Map<String, Object> params);

实现类

 @Override
    public Map<String, Object> selectPageALLItem(Map<String, Object> params) {
        Page<InquiryDto> page = new Query<>(params);
        //将分页传过来的参数params封装到InquiryDto对象中
        InquiryDto inquiryDto = BeanUtil.mapToBean(params, InquiryDto.class, true);

        List<OmsSaleInquiry> omsSaleInquiries = omsSaleInquiryMapper.selectSumInquiry(page, inquiryDto);
        Integer count = omsSaleInquiryMapper.selectAllDocuments(inquiryDto);
        //获取编号的集合
        List<String> collect = omsSaleInquiries.stream().map(OmsSaleInquiry::getBillNo).collect(Collectors.toList());
        List<MakeInquiryVo> voList = null;
        if (collect.size() != 0) {
            voList = omsSaleInquiryItemMapper.selectInquiry(collect, inquiryDto);
        }
        Map<String, Object> map = Maps.newHashMap();
        map.put("records", voList);
        map.put("total", count);
        return map;
    }

3.编写对应的controller层

    @ApiOperation("加入询价")
    @PostMapping(value = "/getInquiry")
    public ActionResult<Map<String, Object>> getInquiry(@RequestParam Map<String, Object> params) {
        Map<String, Object> map = iOmsSaleInquiryItemService.selectPageALLItem(params);
        return new ActionResult<>(StatusCode.SUCCESS, map);
    }

4.显示结果