<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.example.dahua.dao"> <!--<select id="getStudentNum" resultType="String" parameterType="String">--> <!--select student_num--> <!--from SZ_V_School_Student--> <!--where school_id = #{school_id}--> <!--and studentcode = #{studentcode}--> <!--</select>--> </mapper>