SubjectDictMapper.xml

<?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.meishu.mapper.SubjectDictMapper">

    <!-- 通用查询映射结果 -->
    <resultMap id="BaseResultMap" type="com.meishu.model.SubjectDictDO">
        <id column="id" property="id" />
        <result column="create_date" property="createDate" />
        <result column="update_date" property="updateDate" />
        <result column="school" property="school" />
        <result column="grade" property="grade" />
        <result column="classes" property="classes" />
        <result column="class_name" property="className" />
        <result column="subject" property="subject" />
        <result column="subject_en" property="subjectEn" />
        <result column="subject_type" property="subjectType" />
        <result column="session" property="session" />
        <result column="semester" property="semester" />
        <result column="status" property="status" />
        <result column="cover_page_url" property="coverPageUrl" />
        <result column="front_page_url" property="frontPageUrl" />
    </resultMap>

    <!-- 通用查询结果列 -->
    <sql id="Base_Column_List">
        create_date,
        update_date,
        id, school, grade, classes, class_name, subject, subject_en, subject_type, session, semester, status, cover_page_url, front_page_url
    </sql>

    <select id="getClassSubjectName" resultType="string">
       SELECT
            t.`subject`
        FROM
            subject_dict t
        WHERE
            t.delete_date IS NULL
            AND t.grade = #{grade}
            AND t.classes = #{classes}
            AND t.`session` = #{session}
    </select>

</mapper>