我从邮递员发出请求时遇到持久性异常（查询的FROM子句具有com.zomant.entity.Student类，但没有别名）

Question

“我正在基于该2个ID发送两个ID（州ID和城市ID），我需要从数据库中获取一些数据”

// this is my service class

@POST
@Produces({MediaType.APPLICATION_JSON})
@Consumes({MediaType.APPLICATION_JSON})
@Path("/getstatustill")
public Response getStatustill(Statustillrequest statustillrequest, @HeaderParam("Content-Type") String type ) 
{
    Logger custLogger = Logger.getLogger("AdminService.java");
    custLogger.info("=====status till service called");

    List<Statustillresponse> statustillresponse=null;
    try{
        statustillresponse= dao.getStausstills(statustillrequest);
    }catch(Exception e){
        return Response.status(500).type(type).entity(new ErrorResponse("ERR500",  UserPrompts.STATUSTILL_NOTFOUND)).build();
    }
    return null;

}


//this is my DAO class

public List<Statustillresponse> getStausstills(Statustillrequest statustillrequest) {

    Statustillresponse statustillresponse=null;
    List<Statustillresponse> response=new ArrayList<>();

    Logger custLogger = Logger.getLogger("AdminDao.java");
    EntityManagerFactory EMF = EntityManagerFactoryProvider.get();
    EntityManager em = EMF.createEntityManager();
    custLogger.info("entity manager opened at ststus till ");
    int stateid=statustillrequest.getState_id();
    long cityid=statustillrequest.getCity_id();

    long numberofstudents=0;

    try{
        if(stateid==0 && cityid==0){
            custLogger.info("==========entered into all block ");

            numberofstudents= (long) em.createQuery("select count(id)  from testing.Student").getSingleResult();
            statustillresponse.setNumberofstudents(numberofstudents);
        }
        else if(stateid!=0 && cityid==0){
            custLogger.info("==========entered into state one city all ");

            numberofstudents= (long) em.createQuery("SELECT COUNT(ID)  FROM testing.student where STATEID=:stateid")
                    .setParameter("stateid", stateid).getSingleResult();
            statustillresponse.setNumberofstudents(numberofstudents);

        }
        else if(stateid!=0 && cityid!=0){
            custLogger.info("==============entered into state one city one ");

            numberofstudents= (long) em.createQuery("SELECT COUNT(ID)  FROM testing.student where CITYID=:cityid")
                    .setParameter("cityid", cityid).getSingleResult();
            statustillresponse.setNumberofstudents(numberofstudents);

        }
    }catch(Exception e){
        custLogger.warning("error in student count queries========"+e.toString());
    }finally {
        if (em != null) {
            try {
                em.close();
            } catch (Exception ignored) {
                custLogger.info("Couldn't close emFactory :" + ignored);
            }
        }
    }
    response.add(statustillresponse);
    return response;
}

// this is my service class

@POST
@Produces({MediaType.APPLICATION_JSON})
@Consumes({MediaType.APPLICATION_JSON})
@Path("/getstatustill")
public Response getStatustill(Statustillrequest statustillrequest, @HeaderParam("Content-Type") String type ) 
{
    Logger custLogger = Logger.getLogger("AdminService.java");
    custLogger.info("=====status till service called");

    List<Statustillresponse> statustillresponse=null;
    try{
            statustillresponse= dao.getStausstills(statustillrequest);
    }catch(Exception e){
            return Response.status(500).type(type).entity(new ErrorResponse("ERR500",  UserPrompts.STATUSTILL_NOTFOUND)).build();
    }
    return null;

}


//this is my DAO class

public List<Statustillresponse> getStausstills(Statustillrequest statustillrequest) {

    Statustillresponse statustillresponse=null;
    List<Statustillresponse> response=new ArrayList<>();

    Logger custLogger = Logger.getLogger("AdminDao.java");
    EntityManagerFactory EMF = EntityManagerFactoryProvider.get();
    EntityManager em = EMF.createEntityManager();
    custLogger.info("entity manager opened at ststus till ");
    int stateid=statustillrequest.getState_id();
    long cityid=statustillrequest.getCity_id();

    long numberofstudents=0;

    try{
        if(stateid==0 && cityid==0){
            custLogger.info("==========entered into all block ");

            numberofstudents= (long) em.createQuery("select count(id)  from testing.Student").getSingleResult();
            statustillresponse.setNumberofstudents(numberofstudents);
        }
        else if(stateid!=0 && cityid==0){
            custLogger.info("==========entered into state one city all ");

            numberofstudents= (long) em.createQuery("SELECT COUNT(ID)  FROM testing.student where STATEID=:stateid")
                    .setParameter("stateid", stateid).getSingleResult();
            statustillresponse.setNumberofstudents(numberofstudents);

        }
        else if(stateid!=0 && cityid!=0){
            custLogger.info("==============entered into state one city one ");

            numberofstudents= (long) em.createQuery("SELECT COUNT(ID)  FROM testing.student where CITYID=:cityid")
                    .setParameter("cityid", cityid).getSingleResult();
            statustillresponse.setNumberofstudents(numberofstudents);

        }
    }catch(Exception e){
        custLogger.warning("error in student count queries========"+e.toString());
    }finally {
        if (em != null) {
            try {
                em.close();
            } catch (Exception ignored) {
                custLogger.info("Couldn't close emFactory :" + ignored);
            }
        }
    }
    response.add(statustillresponse);
    return response;
}

  

“ [INFO]警告：学生人数错误   query ========= javax.persistence.PersistenceException：类   testing.Student尚未解决。检查查询并   任何导入/别名规范“