使用hibernate Criteria更新多行

Question

我试图在sql中运行更新查询,如下所示:

update studentMaster set sess_status = 'G' where ACADEM_YEAR = COURSE_YEAR;

我试图使用Criteria重新创建查询,如下所示:

public void updateSessionStatus() {
        Session sess = factory.openSession();
        Transaction tx = null;
        try {
            tx = sess.beginTransaction();
            Criteria crit = sess.createCriteria(CollegeStudentsMaster.class);
            crit.add(Restrictions.eqProperty("academicYear", "courseYears"));
            CollegeStudentsMaster e = (CollegeStudentsMaster) crit.uniqueResult();
            e.setSessionStatus("G");
            sess.saveOrUpdate(e);
            tx.commit();
        } catch (HibernateException asd) {
            if (tx != null) {
                tx.rollback();
            }
            log.debug(asd.getMessage());
        } finally {
            sess.close();
        }
    }

这是行不通的,因为满足这个条件的行很多,我的独特结果就是这里的问题.如何将其转换为符合条件的所有行的更新.我不想使用HQL查询,我宁愿使用Criteria.

Answer 1

public void updateSessionStatus() {
        Session sess = factory.openSession();
        Transaction tx = null;
        try {
            tx = sess.beginTransaction();
            Criteria crit = sess.createCriteria(CollegeStudentsMaster.class);
            crit.add(Restrictions.eqProperty("academicYear", "courseYears"));
            // Here is updated code
            ScrollableResults items = crit.scroll();
            int count=0;
            while ( items.next() ) {
                CollegeStudentsMaster e = (CollegeStudentsMaster)items.get(0);
                e.setSessionStatus("G");
                sess.saveOrUpdate(e);
                if ( ++count % 100 == 0 ) {
                    sess.flush();
                    sess.clear();
                }
            }
            tx.commit();
        } catch (HibernateException asd) {
            if (tx != null) {
                tx.rollback();
            }
            log.debug(asd.getMessage());
        } finally {
            sess.close();
        }
    }

总是建议执行非常靠近数据库的批量操作,除非需要,否则我们不需要在会话中保持更新的对象,因此在执行批量操作时尽量避免在会话中加载对象.