测试代码：
package com.hb3.pack_01;
import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;
import com.hb3.pack_01.model.User;
public class BusinessService {
public static void main(String[] args) {Configuration config = new Configuration().configure();SessionFactory sessionFactory = config.buildSessionFactory();Session session = sessionFactory.openSession();//insertUser user = new User();user.setName(“chenyan”);//user.setAge(new Integer(23));Transaction tx = session.beginTransaction();session.save(user);tx.commit();//getuser = (User) session.get(User.class, user.getId());System.out.println(user.getAge());//updateuser.setAge(new Integer(24));tx= session.beginTransaction();session.update(user);tx.commit();
//loaduser = (User) session.load(User.class, user.getId());System.out.println(user.getAge());//deletetx = session.beginTransaction();session.delete(user);tx.commit();session.close();sessionFactory.close();}}执行结果：
11:50:50,750 WARN ConfigurationFactory:127 – No configuration found. Configuring ehcache from ehcache-failsafe.xml found in the classpath: jar:file:/D:/Java/MyEclipse%206.0/workspace/hb3demo/ehcache-1.2.3.jar!/ehcache-failsafe.xml11:50:51,156 WARN EhCacheProvider:93 – Could not find configuration [org.hibernate.cache.UpdateTimestampsCache]; using defaults.11:50:51,171 WARN EhCacheProvider:93 – Could not find configuration [org.hibernate.cache.StandardQueryCache]; using defaults.Hibernate: insert into user (name, age) values (?, ?)nullHibernate: update user set name=?, age=? where id=?24
修改User.hbm.xml文件如下：
运行结果如下：
12:46:32,062 WARN ConfigurationFactory:127 – No configuration found. Configuring ehcache from ehcache-failsafe.xml found in the classpath: jar:file:/D:/Java/MyEclipse%206.0/workspace/hb3demo/ehcache-1.2.3.jar!/ehcache-failsafe.xml12:46:32,468 WARN EhCacheProvider:93 – Could not find configuration [org.hibernate.cache.UpdateTimestampsCache]; using defaults.12:46:32,500 WARN EhCacheProvider:93 – Could not find configuration [org.hibernate.cache.StandardQueryCache]; using defaults.Hibernate: insert into user (name) values (?)nullHibernate: update user set age=? where id=?24Hibernate: delete from user where id=?
可见：
dynamic-insert和dynamic-update设成true后，分别表示生成的SQL中只插入非空字段以及只修改改变过的字段。
另外,hibernate还提供了saveOrUpdate()方法，因为这个方法很容易出错，故在后续章节着重讲述。
关于查询：
1.package com.hb3.pack_01;2.3.import java.util.Iterator;4.import java.util.List;5.6.import org.hibernate.Criteria;7.import org.hibernate.Query;8.import org.hibernate.Session;9.import org.hibernate.SessionFactory;10.import org.hibernate.cfg.Configuration;11.import org.hibernate.criterion.Restrictions;12.13.import com.hb3.pack_01.model.User;14.15.public class BusinessService {16.17. public static void main(String[] args) {18. 19. Configuration config = new Configuration().configure();20. SessionFactory sessionFactory = config.buildSessionFactory(); 21. Session session = sessionFactory.openSession();22. 23. Criteria criteria = session.createCriteria(User.class);24. List<?> users = criteria.list();25. Iterator<?> iterator = users.iterator();26. System.out.println("id /t name/age");27.28. while (iterator.hasNext()) {29. User user = (User) iterator.next();30. System.out.println(user.getId() + " /t " + user.getName() + "/" + user.getAge());31. }32. 33. //criteria.add(Expression.eq("name", "shenbin"));34. criteria.add(Restrictions.eq("name", "shenbin"));35. users = criteria.list();36. iterator = users.iterator();37. System.out.println("id /t name/age");38.39. while (iterator.hasNext()) {40. User user = (User) iterator.next();41. System.out.println(user.getId() + " /t " + user.getName() + "/" + user.getAge());42. }43. 44. System.out.println("====================================================");45. 46. Query query = session.createQuery("from User");47. users = query.list();48. iterator = users.iterator();49. System.out.println("id /t name/age");50.51. while (iterator.hasNext()) {52. User user = (User) iterator.next();53. System.out.println(user.getId() + " /t " + user.getName() + "/" + user.getAge());54. }55. 56. query = session.createQuery("from User user where user.name like ?");57. query.setParameter(0, "shenbin");58. users = query.list();59. iterator = users.iterator();60. System.out.println("id /t name/age");61.62. while (iterator.hasNext()) {63. User user = (User) iterator.next();64. System.out.println(user.getId() + " /t " + user.getName() + "/" + user.getAge());65. }66.67. session.close();68. sessionFactory.close();69. }70.}
执行结果：
13:05:43,031 WARN ConfigurationFactory:127 – No configuration found. Configuring ehcache from ehcache-failsafe.xml found in the classpath: jar:file:/D:/Java/MyEclipse%206.0/workspace/hb3demo/ehcache-1.2.3.jar!/ehcache-failsafe.xml13:05:43,453 WARN EhCacheProvider:93 – Could not find configuration [org.hibernate.cache.UpdateTimestampsCache]; using defaults.13:05:43,484 WARN EhCacheProvider:93 – Could not find configuration [org.hibernate.cache.StandardQueryCache]; using defaults.Hibernate: select this_.id as id0_0_, this_.name as name0_0_, this_.age as age0_0_ from user this_id name/age1 shenbin/292 chenyan/243 chenyan/244 chenyan/24Hibernate: select this_.id as id0_0_, this_.name as name0_0_, this_.age as age0_0_ from user this_ where this_.name=?id name/age1 shenbin/29================================================Hibernate: select user0_.id as id0_, user0_.name as name0_, user0_.age as age0_ from user user0_id name/age1 shenbin/292 chenyan/243 chenyan/244 chenyan/24Hibernate: select user0_.id as id0_, user0_.name as name0_, user0_.age as age0_ from user user0_ where user0_.name like ?id name/age1 shenbin/29
以上分别演示了使用Criteria对SQL的分装以及透过HQL来进行查询。
注意：
代码中如下部分
//criteria.add(Expression.eq(“name”, “shenbin”));criteria.add(Restrictions.eq(“name”, “shenbin”));
在hibernate3.3以后的版本，可能Expression类会被废除，为了保证代码的向后兼容，请使用Restrictions替代。
莫找借口失败，只找理由成功。(不为失败找理由，要为成功找方法)
