springboot MybatisX mapper.xml文件

mapper.xml文件老是写错，今天记录下：

1、mapper.xml，参数问题：使用reqVO

<select id="statisticByAnimal"
        resultType="cn.iocoder.yudao.module.identify.dal.dataobject.result.ResultDO" >
    SELECT lng,lat,animal_id,sum(result_sum) as result_sum FROM identify_result
    <where>
        <if test="reqVO.animalId != null">
            AND animal_id = #{reqVO.animalId}
        </if>
        and deleted=0
    </where>
     GROUP BY lng,lat,animal_id
</select>

调用的方式：

List<ResultDO> statisticByMonthRange(@Param("reqVO") ResultPageReqVO pageReqVO);

2、mapper.xml，参数问题：不使用reqVO，直接通过对象

<select id="statAnimalBeastByMonthCount"        resultType="cn.iocoder.yudao.module.isr.controller.admin.animalbeast.vo.AnimalBeastPageReqVO">
    select TO_CHAR(create_time,'MM') AS create_month, count(1) as coustA
    from isr_animal_beast t
    <where>
        AND deleted=0
        <if test="pid != null and pid !=''">
            AND t.PID=#{pid}
        </if>
        <if test="speciesName != null and speciesName !=''">
            AND t.SPECIES_NAME=#{speciesName}
        </if>
    </where>
    group by TO_CHAR(create_time,'MM')
</select>

调用的方式：

List<AnimalBirdsVO> statAnimalBirdsByMonthCount(AnimalBirdsPageReqVO reqVO);

3、返回类型问题：可以用:resultType="map"

调用使用:List<Map<String, Object>>

下面是完整的代码:

mapper.xml

<select id="statAnimalBirdsByMonthCount" resultType="map">
        select TO_CHAR(create_time,'MM') AS create_month, count(1) as coustA
        from ISR_ANIMAL_BIRDS t
        <where>
            AND deleted=0
            <if test="reqVO.pid != null and reqVO.pid !=''">
                AND t.PID=#{pid}
            </if>
            <if test="reqVO.speciesName != null and reqVO.speciesName !=''">
                AND t.SPECIES_NAME=#{reqVO.speciesName}
            </if>
        </where>
        group by TO_CHAR(create_time,'MM')
    </select>

mapper.java

List<Map<String, Object>> statAnimalBirdsByMonthCount(@Param("reqVO") AnimalBirdsPageReqVO reqVO);

控制层或者业务层调用：

@GetMapping("/statAnimalBirdsByMonthCount")
    @Operation(summary = "获得统计")
    public CommonResult<List<Map<String, Object>>> statAnimalBirdsByMonth(@Valid AnimalBirdsPageReqVO pageReqVO) {
        List<Map<String, Object>> list = animalBirdsMapper.statAnimalBirdsByMonthCount(pageReqVO);
        list.forEach(map->{
            Object month = map.get("create_month");
            System.out.println("month="+month);
        });
        return success(list);
    }