public string setProfessorQuota(string proId, int quota) { ProfessorDao professorDao = new ProfessorDao(); try { if (professorDao.getProfessorById(proId) == null) { return("fail:未找到用户"); } if (professorDao.changeQuotaById(proId, quota)) { return("success"); } return("fail:修改失败"); } catch (Exception e) { return("fail:" + e.Message); } }