关于Sql语句硬编码的问题（求助）

举个例子

 <resultMap='result' namespace="cn.test.UserMapper" >

<select  id="queryAllUserById" resultMap='result''  parameterType="cn.test.User">

<id column="ID" PRoperty="id" jdbcType="NUMERIC" />    <result column="USERNAME" property="username" jdbcType="VARCHAR" />    <result column="PASSWord" property="password" jdbcType="VARCHAR" />

   <result column="IS_DELETED" property="isDeleted" jdbcType="VARCHAR" />

     select

    <if test="distinct" >      distinct    </if>    <include refid="List" />

    from USER        <if test="valid" >      and is_deleted = 'n'    </if>

就是这边sql中 and is_deleted = 'n'中写死了，有什么办法可以解决