ClassDictMapper.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.subsidy.mapper.ClassDictMapper">

    <!-- 通用查询映射结果 -->
    <resultMap id="BaseResultMap" type="com.subsidy.model.ClassDictDO">
        <id column="id" property="id" />
        <result column="create_date" property="createDate" />
        <result column="update_date" property="updateDate" />
        <result column="delete_date" property="deleteDate" />
        <result column="class_name" property="className" />
        <result column="course_id" property="courseId" />
        <result column="start_date" property="startDate" />
        <result column="end_date" property="endDate" />
    </resultMap>

    <!-- 通用查询结果列 -->
    <sql id="Base_Column_List">
        create_date,
        update_date,
        delete_date,
        id, class_name, course_id, start_date, end_date
    </sql>

    <select id="getAllClasses" resultType="com.subsidy.vo.classdict.GetAllClassesVO">
        SELECT
            t.id,
            t.class_name,
            t2.course_name,
            t.start_date,
            t.end_date,
            t4.cnt
        FROM
            class_dict t
            LEFT JOIN course_dict t2 ON t.course_id = t2.id
            LEFT JOIN ( SELECT t3.class_id, sum( 1 ) AS cnt FROM class_member_mapping t3 WHERE t3.delete_date IS NULL GROUP BY t3.class_id ) t4 ON t.id = t4.class_id
        WHERE
            t.delete_date IS NULL
            AND t2.delete_date IS NULL
            and t.company_id = #{companyId}
            and t.class_name like concat('%',#{className} ,'%')
    </select>

</mapper>