Question

Hibernate不会删除我的行：

public boolean deleteVote(Login user, int pid){

      Session session = getSession();

      try{
          String hql = "delete from Vote where uid= :uid AND pid= :pid";
          Query query = session.createQuery(hql);
          System.out.println(user.getUid() + " and pid: " + pid);
          query.setString("uid", user.getUid());
          query.setInteger("pid", pid);
          System.out.println(query.executeUpdate());
      }catch(Exception e){

Outprint：

uid: 123 and pid: 1
Hibernate: delete from votes where uid=? and pid=?
1

当我直接在SQL中尝试时，SQL语法正在运行。直接SQL语法：

 delete from votes where uid= '123' AND pid= 1

映射：

<class name="package.model.Vote" table="votes">
   <id name="vid" column="vid" >
   <generator class="increment"/>
</id>
<property name="pid" column="pid" />
<property name="uid" column="uid" />
<property name="tid" column="tid" />
<property name="votes" column="votes" />
 </class>

表：

CREATE TABLE IF NOT EXISTS `votes` (
  `vid` int(11) NOT NULL 
  `pid` int(11) NOT NULL,
  `uid` varchar(20) NOT NULL,
  `tid` int(11) NOT NULL,
  `votes` int(11) NOT NULL DEFAULT '1',
  PRIMARY KEY (`vid`),
  KEY `pcid` (`pid`,`uid`),
  KEY `uid` (`uid`),
  KEY `tid` (`tid`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=10 ;

ALTER TABLE `votes`
ADD CONSTRAINT `votes_ibfk_3` FOREIGN KEY (`pid`) REFERENCES `poll` (`pid`) ON DELETE CASCADE ON UPDATE CASCADE,
ADD CONSTRAINT `votes_ibfk_4` FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON DELETE CASCADE ON     UPDATE CASCADE,
ADD CONSTRAINT `votes_ibfk_5` FOREIGN KEY (`tid`) REFERENCES `teams` (`tid`) ON DELETE CASCADE ON UPDATE CASCADE;

INSERT INTO `votes` (`vid`, `pid`, `uid`, `tid`, `votes`) VALUES
(20, 1, '123', 1, 1);

我想这很简单，因为到目前为止一切看起来都不错。我没有任何错误或其他任何错误，只是没有删除。

感谢任何帮助。

Answer 1

您需要开始并提交交易。

Transaction transaction = session.beginTransaction();
try {
  // your code
  String hql = "delete from Vote where uid= :uid AND pid= :pid";
  Query query = session.createQuery(hql);
  System.out.println(user.getUid() + " and pid: " + pid);
  query.setString("uid", user.getUid());
  query.setInteger("pid", pid);
  System.out.println(query.executeUpdate());
  // your code end

  transaction.commit();
} catch (Throwable t) {
  transaction.rollback();
  throw t;
}

在更改在数据库中可见之前，您还可能需要关闭会话。

Answer 2

来自您提供的输出

uid: 123 and pid: 1
Hibernate: delete from votes where uid=? and pid=?
1

很明显query.executeUpdate()正在返回1.方法返回更新或删除的实体数量。这意味着已经更新或删除了1行，这没关系。

尝试执行session.flush()来刷新会话，或尝试session.evict()从会话中删除对象。

Answer 3

带有HQL和session.update的完整Java代码

        try {

            try (Session session = this.sessionFactory.openSession()) {

                session.beginTransaction();

                String hql = "UPDATE Employee SET " +
                        "firstName = :firstName, " +
                        "lastName = :lastName," +
                        "gender = :gender," +
                        "jobTitle = :jobTitle," +
                        "departmentId = :departmentId " +
                        "where employeeId = :employeeId";

                Query query = session.createQuery(hql);

                query
                        .setParameter("employeeId", employee.getEmployeeId())
                        .setParameter("departmentId", employee.getDepartmentId())
                        .setParameter("firstName", employee.getFirstName())
                        .setParameter("lastName", employee.getLastName())
                        .setParameter("gender", employee.getGender())
                        .setParameter("jobTitle", employee.getJobTitle())
                ;

                int rows = query.executeUpdate();

//              session.update(Objects.requireNonNull(employee));

                session.getTransaction().commit();

                return session.get(Employee.class, employee.getEmployeeId()).equals(employee);
            }

        } catch (RuntimeException e) {
            e.printStackTrace();
            throw e;
        }

Answer 4

        int deletedRows = 0;
        try {
            session = sessionProvider.get();
            String hql = "delete from ApprovalRemark approvalRemark where approvalRemark.approvalItem.id =:approvalItemId ";
            Query query = session.createQuery(hql);
            query.setParameter("approvalItemId", approvalItemId);
            deletedRows = query.executeUpdate();
        } catch (javax.persistence.NoResultException e) {
            return false;
        } catch (HibernateException he) {
            log.error("deleteAllApprovalRemarksForApprovalItem exception", he);
            throw he;
        }
        log.debug("deleteAllApprovalRemarksForApprovalItem deleted " + deletedRows + " rows");
        return true;

Answer 5

entityManager.createQuery（“DELETE FROM TableName”）。executeUpdate（）;

用Hibernate HQL删除和

5 个答案: