Hibernate5:HQL查询

1. 基本查询

Session session = HibernateUtils.openSession(); Transaction tx = session.beginTransaction() String hql = "from Customer"; Query query = session.createQuery(hql); List list = query.list(); System.out.println(list); tx.commit(); session.close();

2. 条件查询

2.1 基本条件查询

Session session = HibernateUtils.openSession(); Transaction tx = session.beginTransaction(); //查询出唯一一个结果 String hql = "from Customer where cust_id = 1"; Query query = session.createQuery(hql); Customer customer = (Customer) query.uniqueResult(); System.out.println(customer); tx.commit(); session.close();

2.2 问号占位符查询

Session session = HibernateUtils.openSession(); Transaction tx = session.beginTransaction(); //问号占位符 String hql = "from Customer where cust_id = ?"; Query query = session.createQuery(hql); query.setParameter(0, 2l); Customer customer = (Customer) query.uniqueResult(); System.out.println(customer); tx.commit(); session.close();

2.3. 命名占位符查询

Session session = HibernateUtils.openSession(); Transaction tx = session.beginTransaction(); //命名占位符 String hql = "from Customer where cust_id = :cust_id"; Query query = session.createQuery(hql); query.setParameter("cust_id", 2l); Customer customer = (Customer) query.uniqueResult(); System.out.println(customer); tx.commit(); session.close();

3. 分页查询

Session session = HibernateUtils.openSession(); Transaction tx = session.beginTransaction(); //分页查询 String hql = "from Customer"; Query query = session.createQuery(hql); //相当于limit ?,?中的两个问号 query.setFirstResult(4); query.setMaxResults(2); List list = query.list(); System.out.println(list); tx.commit(); session.close();