mybatis中只有一个参数而且还要if判断

There is no getter for property named 'userid ’ in 'class java.lang.Integer

<--当传入数据只有一个时mybatis中<if>判断会出现判断条件里不管你传什么参，只能用_parameter 代替-->
<select id="selectUserById"  parameterType="java.lang.Integer" resultType="java.util.Map">
        select 
        <include refid="Base_Column_List" />
        from user
        <if test="_parameter != null">
        where userid = #{_parameter,jdbcType=INTEGER}
        </if>
</select>