數據庫已更新，但選擇查詢未在休眠狀態下提供結果

Question

我在Hibernate上使用JPA，並且它以TokuDb作為引擎連接到MariaDb。

我正在運行一個無限循環，該循環正在檢查表是否基於某些標志有新行，如果找到新行，則對其進行處理。

但是，如果循環運行，如果您使用不同的線程/機制將數據插入表中，則會發生問題，JPA查詢未找到結果，因此始終不返回任何新行。 代碼如下

do {
        try {
            if (!em.isOpen()) {
                em = PersistenceLocal.getEntityManager();
            }
            TypedQuery<FileMaster> query = em.createQuery("SELECT f FROM FileMaster f WHERE f.misUpdated = :misUpdated AND f.status = :status", FileMaster.class);
            query.setParameter("misUpdated", false);
            query.setParameter("status", "sent");
            query.set
            List<FileMaster> result = query.getResultList();
            if (result.size() > 0) {

                EntityTransaction tx = em.getTransaction();
                tx.begin();
                for (FileMaster fm : result) {

                    SimpleDateFormat dateFormat = new SimpleDateFormat("YYYY-MM-dd");
                    String dt = dateFormat.format(fm.getSheduleDate());

                    // find out what is the uid in file master
                    TypedQuery<Misthird> misthird = em.createNamedQuery("Misthird.findByPrimarKey", Misthird.class);

                    misthird.setParameter("uid", Integer.valueOf(fm.getCrn()));
                    misthird.setParameter("dt", fm.getSheduleDate(), TemporalType.DATE);
                    Misthird m;
                    try {
                        m = misthird.getSingleResult();
                    } catch (Exception ex) {
                        m = new Misthird(Integer.valueOf(fm.getCrn()), fm.getSheduleDate());
                    }
                    Calendar c = Calendar.getInstance();
                    c.setTime(fm.getSheduleDate());
                    //System.out.println("Scheduled Date = "+fm.getSheduleDate());
                    int hr = c.get(Calendar.HOUR_OF_DAY);
                    System.out.println("Hour = " + hr);
                    switch (hr) {
                        case 0:
                            m.setHr(m.getHr() + fm.getTRecord());
                            break;
                        case 1:
                            m.setHr1(m.getHr1() + fm.getTRecord());
                            break;
                        case 2:
                            m.setHr2(m.getHr2() + fm.getTRecord());
                            break;
                        case 3:
                            m.setHr3(m.getHr3() + fm.getTRecord());
                            break;
                        case 4:
                            m.setHr4(m.getHr4() + fm.getTRecord());
                            break;
                        case 5:
                            m.setHr5(m.getHr5() + fm.getTRecord());
                            break;
                        case 6:
                            m.setHr6(m.getHr6() + fm.getTRecord());
                            break;
                        case 7:
                            m.setHr7(m.getHr7() + fm.getTRecord());
                            break;
                        case 8:
                            m.setHr8(m.getHr8() + fm.getTRecord());
                            break;
                        case 9:
                            m.setHr9(m.getHr9() + fm.getTRecord());
                            break;
                        case 10:
                            m.setHr10(m.getHr10() + fm.getTRecord());
                            break;
                        case 11:
                            m.setHr11(m.getHr11() + fm.getTRecord());
                            break;
                        case 12:
                            m.setHr12(m.getHr12() + fm.getTRecord());
                            break;
                        case 13:
                            m.setHr13(m.getHr13() + fm.getTRecord());
                            break;
                        case 14:
                            m.setHr14(m.getHr14() + fm.getTRecord());
                            break;
                        case 15:
                            m.setHr15(m.getHr15() + fm.getTRecord());
                            break;
                        case 16:
                            m.setHr16(m.getHr16() + fm.getTRecord());
                            break;
                        case 17:
                            m.setHr17(m.getHr17() + fm.getTRecord());
                            break;
                        case 18:
                            m.setHr18(m.getHr18() + fm.getTRecord());
                            break;
                        case 19:
                            m.setHr19(m.getHr19() + fm.getTRecord());
                            break;
                        case 20:
                            m.setHr20(m.getHr20() + fm.getTRecord());
                            break;
                        case 21:
                            m.setHr21(m.getHr21() + fm.getTRecord());
                            break;
                        case 22:
                            m.setHr22(m.getHr22() + fm.getTRecord());
                            break;
                        case 23:
                            m.setHr23(m.getHr23() + fm.getTRecord());
                            break;
                    }
                    // update total records 
                    m.setTot(m.getTot() + fm.getTRecord());
                    System.out.println("Total = " + m.getTot());
                    if (em.contains(m)) {
                        em.persist(m);
                    } else {
                        m = em.merge(m);
                        em.persist(m);
                    }
                    // create a new table for fileid and misupdated status, use trigger and keep filemaster free.

                    if (!em.contains(fm)) {
                        fm = em.merge(fm);
                    }

                    fm.setMisUpdated(true);
                    em.persist(fm);
                }

                System.out.println("MIS updated and Transaction Commited " + new Date());

                tx.commit();
            }

        } catch (Exception ex) {

            ex.printStackTrace();
        } finally {
            try {
                em.close();
                Thread.sleep(1000);
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
    } while (cron_mode);
}

的SQL

Hibernate: select filemaster0_.FileID as FileID1_3_, filemaster0_.after_rev as after_re2_3_, filemaster0_.apx_priotity as apx_prio3_3_, filemaster0_.befor_rev as befor_re4_3_, filemaster0_.cancel_date as cancel_d5_3_, filemaster0_.cp as cp6_3_, filemaster0_.credit as credit7_3_, filemaster0_.CRN as CRN8_3_, filemaster0_.cut as cut9_3_, filemaster0_.dnd_Checked as dnd_Che10_3_, filemaster0_.download_status as downloa11_3_, filemaster0_.FileName as FileNam12_3_, filemaster0_.gateway as gateway13_3_, filemaster0_.is_credit_revers as is_cred14_3_, filemaster0_.is_credit_reversed as is_cred15_3_, filemaster0_.mis_updated as mis_upd16_3_, filemaster0_.modem_distibute as modem_d17_3_, filemaster0_.msg as msg18_3_, filemaster0_.pid as pid19_3_, filemaster0_.priority as priorit20_3_, filemaster0_.sender_id as sender_21_3_, filemaster0_.shedule_date as shedule22_3_, filemaster0_.signature as signatu23_3_, filemaster0_.Status as Status24_3_, filemaster0_.t_record as t_recor25_3_, filemaster0_.t_reversal as t_rever26_3_, filemaster0_.type as type27_3_, filemaster0_.unicode as unicode28_3_, filemaster0_.UploadDate as UploadD29_3_ from file_master filemaster0_ where filemaster0_.mis_updated=? and filemaster0_.Status=?

Answer 1

您可以在em.close()之前執行session.flush() （在您的情況下為em.flush() ），它可能會起作用。

Answer 2

交易完成后，我使用了提示並清除了entitymanager。

   query.setHint("javax.persistence.cache.retrieveMode", CacheStoreMode.BYPASS);
   query.setHint("javax.persistence.cache.storeMode", CacheStoreMode.BYPASS);