TeacherMapper.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.TeacherMapper">

    <select id="teacherCollege" parameterType="long" resultType="com.subsidy.model.CollegesDictDO">
        SELECT
            t2.*
        FROM
            teacher t
            LEFT JOIN colleges_dict t2 ON t.college_id = t2.id
        WHERE
            t.delete_date IS NULL
            AND t2.delete_date IS NULL
            AND t.id = #{teacherId}
    </select>

</mapper>