MyBatis的传入参数parameterType类型

心已赠人 2022-09-21 08:04 222阅读 0赞

**1. MyBatis的传入参数parameterType类型分两种**

1. 1. 基本数据类型：int,string,long,Date;

1. 2. 复杂数据类型：类和Map

**2. 如何获取参数中的值:**

2.1  基本数据类型：\#\{参数\} 获取参数中的值

2.2  复杂数据类型：\#\{属性名\}  ，map中则是\#\{key\}

**3.案例：**

3.1 基本数据类型案例

<sql id="Base_Column_List" >
        id, car_dept_name, car_maker_name, icon,car_maker_py,hot_type
      </sql>
      <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Long" >
        select 
        <include refid="Base_Column_List" />
        from common_car_make
        where id = #{id,jdbcType=BIGINT}
      </select>

3.2 复杂类型--map类型

<select id="queryCarMakerList" resultMap="BaseResultMap" parameterType="java.util.Map">
            select
            <include refid="Base_Column_List" />
            from common_car_make cm
            where 1=1
            <if test="id != null">
                and  cm.id = #{id,jdbcType=DECIMAL}
            </if>
            <if test="carDeptName != null">
                and  cm.car_dept_name = #{carDeptName,jdbcType=VARCHAR}
            </if>
            <if test="carMakerName != null">
                and  cm.car_maker_name = #{carMakerName,jdbcType=VARCHAR}
            </if>
            <if test="hotType != null" >
               and  cm.hot_type = #{hotType,jdbcType=BIGINT}
            </if>
            ORDER BY cm.id
        </select>

3.3 复杂类型--类类型

<update id="updateByPrimaryKeySelective" parameterType="com.epeit.api.model.CommonCarMake" >
        update common_car_make
        <set >
          <if test="carDeptName != null" >
            car_dept_name = #{carDeptName,jdbcType=VARCHAR},
          </if>
          <if test="carMakerName != null" >
            car_maker_name = #{carMakerName,jdbcType=VARCHAR},
          </if>
          <if test="icon != null" >
            icon = #{icon,jdbcType=VARCHAR},
          </if>
          <if test="carMakerPy != null" >
                car_maker_py = #{carMakerPy,jdbcType=VARCHAR},
          </if>
          <if test="hotType != null" >
                hot_type = #{hotType,jdbcType=BIGINT},
          </if>
        </set>
        where id = #{id,jdbcType=BIGINT}
      </update>

3.4 复杂类型--map中包含**数组**的情况

<select id="selectProOrderByOrderId" resultType="com.epeit.api.model.ProOrder" parameterType="java.util.HashMap" >
            select sum(pro_order_num) proOrderNum,product_id productId,promotion_id promotionId
            from pro_order
            where 1=1
            <if test="orderIds != null">
              and
                <foreach collection="orderIds" item="item" open="order_id IN(" separator="," close=")">
                    #{item,jdbcType=BIGINT}
                </foreach>
            </if>
            GROUP BY product_id,promotion_id
        </select>

4.注解@Param：这个比较特殊，但是很好理解

**案例一：**

@Param(value="startdate") String startDate ：注解单一属性；这个类似于将参数重命名了一次

如调用mybatis的\*mapper.xml中配置sql语句（DAO层）

List<String> selectIdBySortTime(@Param(value="startdate")String startDate);

则xml中的语句，需要配合@param括号中的内容: **参数为startdate**

<select id="selectIdBySortTime" resultType="java.lang.String" parameterType="java.lang.String">
      	select distinct ajlcid from ebd_fh_ajlc where sorttime >= to_date(#{startdate,jdbcType=VARCHAR},'YYYY-MM-DD') and created_date=updated_date 
      	and keyvalue in (select  distinct companyname from ebd_fh_company_list where isupdate='0')
       </select>

案例二：

注解javaBean,@Param(value="dateVo") DateVo dateVo；则需要注意编写的参数

List<String> selectIds(@Param(value="dateVo")DateVo dateVo);

对应的mapping文件

<select id="selectIds" resultType="java.lang.String" parameterType="com.api.entity.DateVo">
      	select distinct ajlcid from ebd_fh_ajlc where sorttime >= to_date(#       {dateVo.startDate,jdbcType=VARCHAR},'YYYY-MM-DD') and created_date=updated_date 
      	and keyvalue in (select  distinct companyname from ebd_fh_company_list where isupdate='0')
     </select>

至于要说优缺点的话，看个人喜好