一、发现问题<select id="queryStudentByNum" resultType="student" parameterType="string">  select num,name,phone from student  <where> <if test = " num!=null and num!=‘‘ ">AND num = #{num}</if></where></select> Mybatis查询传入一个字符串传参数，报There is no getter for property named ‘num‘ in ‘class java.lang.String‘。二、解决问题<select id="queryStudentByNum" resultType="student" parameterType="string">  select num,name,phone from student  <where> <if test = " _parameter!=null and_parameter!=‘‘ ">AND num = #{_parameter}</if></where></select>无论参数名，都要改成"_parameter"。三、原因分析Mybatis默认采用ONGL解析参数，所以会自动采用对象树的形式取string.num值，引起报错。也可以public List methodName(@Param(value="num") String num)的方法说明参数值