mysql dynamic order by

<if test="param.sortName!=null and param.sortBy!=null and param.sortName!='' and param.sortBy!=''">
            order by
            ${@org.apache.commons.lang.StringEscapeUtils@escapeSql(param.sortName)}
            ${@org.apache.commons.lang.StringEscapeUtils@escapeSql(param.sortBy)}
        </if>