mybatis 里面怎么按照条件查询和查询全部数据 这两个在同一接口里面？

    <select id="selectTouristGenderYearhList" resultType="com.zdxf.domain.TouristGenderDO">
        select * from pw_tourist_gender_year
        <where>
            1=1
            <if test="id != null">
                and id = #{id}
            </if>
        </where>
    </select>