AcademyMajorDictMapper.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.AcademyMajorDictMapper">

    <select id="majors" resultType="com.subsidy.model.AcademyMajorDictDO">
        SELECT
            *
        FROM
            academy_major_dict t
            where t.delete_date is null
            and t.college_id = #{collegeId}
            <if test="major != null and major != ''">
                and t.major like concat('%',#{major} ,'%')
            </if>
    </select>

</mapper>