</set> WHERE id_ = #{id} AND update_time_=#{updateTime}
</update>
-
- <!-- 根据主键删除一条记录 -->
+
+ <update id="updateExamRoomStudentNum">
+ UPDATE exam_room er
+ LEFT JOIN ( SELECT exam_room_id_, COUNT( exam_registration_id_ ) stu_num_ FROM exam_room_student_relation WHERE examination_basic_id_ = #{examId} GROUP BY exam_room_id_ ) ers ON er.id_ = ers.exam_room_id_