SpringBoot实战：多表联查

1. 保存和更新公寓信息

请求数据的结构 

@Schema(description = "公寓信息")
@Data
public class ApartmentSubmitVo extends ApartmentInfo {

    @Schema(description="公寓配套id")
    private List<Long> facilityInfoIds;

    @Schema(description="公寓标签id")
    private List<Long> labelIds;

    @Schema(description="公寓杂费值id")
    private List<Long> feeValueIds;

    @Schema(description="公寓图片id")
    private List<GraphVo> graphVoList;

}

Controller层

    @Operation(summary = "保存或更新公寓信息")
    @PostMapping("saveOrUpdate")
    public Result saveOrUpdate(@RequestBody ApartmentSubmitVo apartmentSubmitVo) {
        apartmentInfoService.saveOrUpdateApartment(apartmentSubmitVo);
        return Result.ok();
    }

Service层

 void saveOrUpdateApartment(ApartmentSubmitVo apartmentSubmitVo);

/**
     * 保存或更新公寓信息
     *
     * @param apartmentSubmitVo 公寓信息提交对象
     *                          若传入公寓ID为空，则执行插入操作；若不为空，则执行更新操作
     *                          更新操作时会先删除原有配套、杂费、标签和图片信息，再插入新的信息
     */
    @Override
    public void saveOrUpdateApartment(ApartmentSubmitVo apartmentSubmitVo) {
        //保存或修改公寓信息：
        //1.判断该参数id是否为空，为空：插入的新数据 不为空：修改数据
        boolean isUpdate = apartmentSubmitVo.getId() != null;
        //2.调用父类保存或修改方法，将公寓基本信息进行保存
        super.saveOrUpdate(apartmentSubmitVo);

        if (isUpdate) {
            //修改数据：直接将所有原数据删除后重新插入
            //1.删除配套
            LambdaQueryWrapper<ApartmentFacility> facilityLambdaQueryWrapper = new LambdaQueryWrapper<>();
            facilityLambdaQueryWrapper.eq(ApartmentFacility::getApartmentId, apartmentSubmitVo.getId());
            facilityService.remove(facilityLambdaQueryWrapper);

            //2.删除杂费
            LambdaQueryWrapper<ApartmentFeeValue> feeValueLambdaQueryWrapper = new LambdaQueryWrapper<>();
            feeValueLambdaQueryWrapper.eq(ApartmentFeeValue::getFeeValueId, apartmentSubmitVo.getId());
            feeValueService.remove(feeValueLambdaQueryWrapper);

            //3.删除标签
            LambdaQueryWrapper<ApartmentLabel> labelLambdaQueryWrapper = new LambdaQueryWrapper<>();
            labelLambdaQueryWrapper.eq(ApartmentLabel::getLabelId, apartmentSubmitVo.getId());
            labelService.remove(labelLambdaQueryWrapper);

            //4.删除图片
            LambdaQueryWrapper<GraphInfo> graphInfoLambdaQueryWrapper = new LambdaQueryWrapper<>();
            graphInfoLambdaQueryWrapper.eq(GraphInfo::getId, apartmentSubmitVo.getId());
            graphInfoService.remove(graphInfoLambdaQueryWrapper);
        }

        //1.插入配套
        List<Long> facilityInfoIdsList = apartmentSubmitVo.getFacilityInfoIds();
        if (!CollectionUtils.isEmpty(facilityInfoIdsList)) {
            ArrayList<ApartmentFacility> facilityArrayList = new ArrayList<>();
            for (Long facilityId : facilityInfoIdsList) {
                ApartmentFacility apartmentFacility = ApartmentFacility.builder().build();
                apartmentFacility.setFacilityId(facilityId);
                apartmentFacility.setApartmentId(apartmentSubmitVo.getId());
                facilityArrayList.add(apartmentFacility);
            }
            facilityService.saveBatch(facilityArrayList);
        }

        //2.插入杂费
        List<Long> feeValueIds = apartmentSubmitVo.getFeeValueIds();
        if (!CollectionUtils.isEmpty(feeValueIds)) {
            ArrayList<ApartmentFeeValue> apartmentFeeValueList = new ArrayList<>();
            for (Long feeValueId : feeValueIds) {
                ApartmentFeeValue apartmentFeeValue = ApartmentFeeValue.builder().build();
                apartmentFeeValue.setApartmentId(apartmentSubmitVo.getId());
                apartmentFeeValue.setFeeValueId(feeValueId);
                apartmentFeeValueList.add(apartmentFeeValue);
            }
            feeValueService.saveBatch(apartmentFeeValueList);
        }

        //3.插入标签
        List<Long> labelIds = apartmentSubmitVo.getLabelIds();
        if (!CollectionUtils.isEmpty(labelIds)) {
            ArrayList<ApartmentLabel> apartmentLabelArrayList = new ArrayList<>();
            for (Long labelId : labelIds) {
                ApartmentLabel apartmentLabel = ApartmentLabel.builder().build();
                apartmentLabel.setApartmentId(apartmentSubmitVo.getId());
                apartmentLabel.setLabelId(labelId);
                apartmentLabelArrayList.add(apartmentLabel);
            }
            labelService.saveBatch(apartmentLabelArrayList);
        }

        //4.插入图片
        List<GraphVo> graphVoList = apartmentSubmitVo.getGraphVoList();
        if (!CollectionUtils.isEmpty(graphVoList)) {
            ArrayList<GraphInfo> graphInfos = new ArrayList<>();
            for (GraphVo graphVo : graphVoList) {
                GraphInfo graphInfo = new GraphInfo();
                graphInfo.setItemType(ItemType.APARTMENT);
                graphInfo.setItemId(apartmentSubmitVo.getId());
                graphInfo.setName(graphVo.getName());
                graphInfo.setUrl(graphVo.getUrl());
                graphInfos.add(graphInfo);
            }
            graphInfoService.saveBatch(graphInfos);
        }
    }

2. 根据条件分页查询

请求数据结构

@Data
@Schema(description = "公寓查询实体")
public class ApartmentQueryVo {

    @Schema(description = "省份id")
    private Long provinceId;

    @Schema(description = "城市id")
    private Long cityId;

    @Schema(description = "区域id")
    private Long districtId;
}

 响应数据结构

@Data
@Schema(description = "后台管理系统公寓列表实体")
public class ApartmentItemVo extends ApartmentInfo {

    @Schema(description = "房间总数")
    private Long totalRoomCount;

    @Schema(description = "空闲房间数")
    private Long freeRoomCount;

}

Controller层

    @Operation(summary = "根据条件分页查询公寓列表")
    @GetMapping("pageItem")
    public Result<IPage<ApartmentItemVo>> pageItem(@RequestParam long current, @RequestParam long size, ApartmentQueryVo queryVo) {
        Page<ApartmentItemVo> page = new Page<>(current, size);
        IPage<ApartmentItemVo> result = apartmentInfoService.pageItem(page, queryVo);
        return Result.ok(result);
    }

Service层

IPage<ApartmentItemVo> pageItem(Page<ApartmentItemVo> page, ApartmentQueryVo queryVo);

    @Override
    public IPage<ApartmentItemVo> pageItem(Page<ApartmentItemVo> page, ApartmentQueryVo queryVo) {
        return apartmentInfoMapper.pageItem(page, queryVo);
    }

Mapper层

IPage<ApartmentItemVo> pageApartmentItemByQuery(IPage<ApartmentItemVo> page, ApartmentQueryVo queryVo);

多表联查大sql

    <select id="pageItem" resultType="com.atguigu.lease.web.admin.vo.apartment.ApartmentItemVo">
        select ai.id,
               ai.name,
               ai.introduction,
               ai.district_id,
               ai.district_name,
               ai.city_id,
               ai.city_name,
               ai.province_id,
               ai.province_name,
               ai.address_detail,
               ai.latitude,
               ai.longitude,
               ai.phone,
               ai.is_release,
               ifnull(tc.cnt, 0)                     total_room_count,
               ifnull(tc.cnt, 0) - ifnull(cc.cnt, 0) free_room_count
        from (select id,
                     name,
                     introduction,
                     district_id,
                     district_name,
                     city_id,
                     city_name,
                     province_id,
                     province_name,
                     address_detail,
                     latitude,
                     longitude,
                     phone,
                     is_release
              from apartment_info
                <where>
                    is_deleted=0
                    <if test="queryVo.provinceId != null">
                        and province_id=#{queryVo.provinceId}
                    </if>
                    <if test="queryVo.cityId != null">
                        and city_id=#{queryVo.cityId}
                    </if>
                    <if test="queryVo.districtId != null">
                        and district_id=#{queryVo.districtId}
                    </if>
                </where>) ai
                 left join
             (select apartment_id,
                     count(*) cnt
              from room_info
              where is_deleted = 0
                and is_release = 1
              group by apartment_id) tc
             on ai.id = tc.apartment_id
                 left join
             (select apartment_id,
                     count(*) cnt
              from lease_agreement
              where is_deleted = 0
                and status in (2, 5)
              group by apartment_id) cc
             on ai.id = cc.apartment_id
    </select>

knife4j调整传递参数

默认情况下Knife4j为该接口生成的接口文档如下图所示，其中的queryVo参数不方便调试 

可在application.yml文件中增加如下配置，将queryVo做打平处理

springdoc:
  default-flat-param-object: true

 3. 根据ID获取公寓详细信息

响应数据

@Schema(description = "公寓信息")
@Data
public class ApartmentDetailVo extends ApartmentInfo {

    @Schema(description = "图片列表")
    private List<GraphVo> graphVoList;

    @Schema(description = "标签列表")
    private List<LabelInfo> labelInfoList;

    @Schema(description = "配套列表")
    private List<FacilityInfo> facilityInfoList;

    @Schema(description = "杂费列表")
    private List<FeeValueVo> feeValueVoList;
}

 Controller层

    @Operation(summary = "根据ID获取公寓详细信息")
    @GetMapping("getDetailById")
    public Result<ApartmentDetailVo> getDetailById(@RequestParam Long id) {
        ApartmentDetailVo apartmentDetailVo = apartmentInfoService.getDetailById(id);
        return Result.ok(apartmentDetailVo);
    }

Service层

ApartmentDetailVo getDetailById(Long id);

    @Override
    public ApartmentDetailVo getDetailById(Long id) {
        //1.查询公寓基本信息
        ApartmentInfo apartmentInfo = apartmentInfoMapper.selectById(id);

        //2.查询图片列表
        List<GraphVo> graphVoList = graphInfoMapper.selectGraphVoList(id, ItemType.APARTMENT);

        //3.查询标签列表
        List<LabelInfo> labelInfoList = labelInfoMapper.selectLabelInfoList(id); //通过公寓id查询出所有标签id，在通过标签id查出所有标签信息

        //4.查询配套列表
        List<FacilityInfo> facilityInfoList = facilityInfoMapper.selectFacilityInfoList(id); //通过公寓id查询出所有配套id，在通过配套id查出所有配套信息

        //5.查询杂费列表
        List<FeeValueVo> feeValueList = feeValueMapper.selectFeeValueList(id); //通过公寓id查询出所有杂费值id，在通过杂费值id查出所有杂费以及杂费名称id，再通过杂费名称id查出杂费名

        //6.组装结果
        ApartmentDetailVo apartmentDetailVo = new ApartmentDetailVo();
        BeanUtils.copyProperties(apartmentInfo, apartmentDetailVo);
        apartmentDetailVo.setGraphVoList(graphVoList);
        apartmentDetailVo.setLabelInfoList(labelInfoList);
        apartmentDetailVo.setFacilityInfoList(facilityInfoList);
        apartmentDetailVo.setFeeValueVoList(feeValueList);

        return apartmentDetailVo;
    }

Mapper。。。

4. 根据ID删除公寓信息

    @Operation(summary = "根据id删除公寓信息")
    @DeleteMapping("removeById")
    public Result removeById(@RequestParam Long id) {
        apartmentInfoService.removeApartmentById(id);
        return Result.ok();
    }