測試代碼：
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();
//insert
User user = new User();
user.setName("chenyan");
//user.setAge(new Integer(23));
Transaction tx = session.beginTransaction();
session.save(user);
tx.commit();
//get
user = (User) session.get(User.class, user.getId());
System.out.println(user.getAge());
//update
user.setAge(new Integer(24));
tx= session.beginTransaction();
session.update(user);
tx.commit();
//load
user = (User) session.load(User.class, user.getId());
System.out.println(user.getAge());
//delete
tx = session.beginTransaction();
session.delete(user);
tx.commit();
session.close();
sessionFactory.close();
}
}
執行結果：
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.xml
11:50:51,156 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 (?, ?)
null
Hibernate: update user set name=?, age=? where id=?
24
修改User.hbm.xml文件如下：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.hb3.pack_01.model.User" table="user"
dynamic-insert="true"
dynamic-update="true"
>
<id name="id" column="id" type="java.lang.Integer">
<generator class="native" />
</id>
<property name="name" column="name" type="java.lang.String" />
<property name="age" column="age" type="java.lang.Integer" />
</class>
</hibernate-mapping>
運行結果如下：
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.xml
12:46:32,468 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 (?)
null
Hibernate: update user set age=? where id=?
24
Hibernate: delete from user where id=?
可見：
dynamic-insert和dynamic-update設成true後，分別表示生成的SQL中只插入非空字段以及只修改改變過的字段。
另外,hibernate還提供了saveOrUpdate()方法，因為這個方法很容易出錯，故在後續章節著重講述。
關於查詢：
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.}
執行結果：
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.xml
13:05:43,453 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/age
1 shenbin/29
2 chenyan/24
3 chenyan/24
4 chenyan/24
Hibernate: select this_.id as id0_0_, this_.name as name0_0_, this_.age as age0_0_ from user this_ where this_.name=?
id name/age
1 shenbin/29
================================================
Hibernate: select user0_.id as id0_, user0_.name as name0_, user0_.age as age0_ from user user0_
id name/age
1 shenbin/29
2 chenyan/24
3 chenyan/24
4 chenyan/24
Hibernate: select user0_.id as id0_, user0_.name as name0_, user0_.age as age0_ from user user0_ where user0_.name like ?
id name/age
1 shenbin/29
以上分別演示了使用Criteria對SQL的分裝以及透過HQL來進行查詢。
注意：
代碼中如下部分
//criteria.add(Expression.eq("name", "shenbin"));
criteria.add(Restrictions.eq("name", "shenbin"));
在hibernate3.3以後的版本，可能Expression類會被廢除，為了保證代碼的向後兼容，請使用Restrictions替代。
