mybatis 传入null值的解决方案

public String getPersonInfo(@PathParam("Name") String Name, @PathParam("IDCard") String IDCard)

public List<Map> getPersonInfo(@Param("name") String name, @Param("idcard") String idcard);

<if test="name == null or name == '0'.toString()"> 
    <![CDATA[ and (b.identity_id = #{idcard,javaType=String,jdbcType=VARCHAR})
    group by name,id_card,birthTime,sex  ]]> 
</if>

        if (Name == null || "null".equalsIgnoreCase(Name)) {
            Name = null;
        }
        if (IDCard == null || "null".equalsIgnoreCase(IDCard)) {
            IDCard = null;
        }

    public int delExhibion(List<String> ids){
        Integer result = null;
        ExhibitionManager exhibitionManager = new ExhibitionManager();
        for (String id : ids){
            exhibitionManager.setId(id);
            exhibitionManager.setDelFlag("1");
             result += exhibitionManagerMapper.delete(id);
        }
        return result;
    }

int delete(@Param("id") String id);  

int delete(Object dx);

<delete id="delete" parameterType="java.lang.String" >  
         SELECT * FROM table
         <where>  
                   <if test="_parameter != null">  
                            AND id= #{id}  
                   </if>  
         </where>  
</select>

    public int delExhibion(List<String> ids){
        Integer result = null;
        for (String id : ids){
             result += exhibitionManagerMapper.delete(id);
        }
        return result;
    }

Integer result = null;
result =  exhibitionManagerMapper.delete(id);

 public int delExhibion(List<String> ids){
        Integer result = 0;
        for (String id : ids){
             result += exhibitionManagerMapper.delete(id);
        }
        return result;
    }