通过hibernate访问postgreSQL的搭建过程

postgreSQL jdbc jar包引入   在pom.xml中写依赖:

<dependency>   <groupId>postgresql</groupId>   <artifactId>postgresql</artifactId>   <version>9.1-901-1.jdbc4</version> </dependency>

<?xml version=‘1.0‘ encoding=‘utf-8‘?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "src/resource/schema/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>
        <!-- Database connection settings -->
        <!-- Database connection settings -->
        <property name="connection.driver_class">
            org.postgresql.Driver
        </property>
        <property name="connection.url">
            jdbc:postgresql://10.21.132.19:5432/test
        </property>
        <property name="connection.username">postgres</property>
        <property name="connection.password">88075998</property>


        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>

        <!-- SQL dialect -->
        <property name="dialect">
            org.hibernate.dialect.PostgreSQLDialect
        </property>

        <!-- Enable Hibernate‘s automatic session context management -->
        <property name="current_session_context_class">thread</property>

        <!-- Disable the second-level cache  
        <property name="cache.provider_class">
            org.hibernate.cache.internal.NoCacheProvider
        </property>-->

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">false</property>

        <!-- Drop and re-create the database schema on startup -->
        <!-- <property name="hbm2ddl.auto">update</property> -->

        <!-- <mapping resource="com/hik/gss/sys/domain/User.hbm.xml" />-->
        
        <mapping class="model.User"></mapping>
    </session-factory>

</hibernate-configuration>

1. 实体类的定义,如下:

   package model;
   
   import org.hibernate.annotations.GenericGenerator;
   
   import javax.persistence.*;
   
   @Entity
   @Table(name="public.user")
   public class User {
       private Integer userId;
       private String userName;
       private String passWord;
   
       @Id
       @GeneratedValue(generator="increment")
       @GenericGenerator(name="increment", strategy = "increment")
       @Column(name = "user_id")
       public Integer getUserId() {
           return userId;
       }
   
       public void setUserId(Integer userId) {
           this.userId = userId;
       }
   
       @Column(name = "username")
       public String getUserName() {
           return userName;
       }
   
       public void setUserName(String userName) {
           this.userName = userName;
       }
   
       @Column(name = "password")
       public String getPassWord() {
           return passWord;
       }
   
       public void setPassWord(String passWord) {
           this.passWord = passWord;
       }
   
   
   
   
   }

   
   注解说明:@Entity实体类标注,    @Table标注表名,注意表名前面要写模式名(public),被坑过.   @Id 表示主键   @Column列名  

2. 查询数据库代码Demo:

           final StandardServiceRegistry registry = new StandardServiceRegistryBuilder()
                   .configure()                 .build();
            SessionFactory sessionFactory = null;
           try {
               sessionFactory = new MetadataSources( registry ).buildMetadata().buildSessionFactory();
           } catch (Exception e) {
               // The registry would be destroyed by the SessionFactory, but we had trouble building the SessionFactory
               // so destroy it manually.
               StandardServiceRegistryBuilder.destroy( registry );
           }
   
           Session session = sessionFactory.openSession();
           session.beginTransaction();
           List result = session.createQuery( "from model.User" ).list();
           for ( User user : (List<User>) result ) {
               System.out.println( "User (" + user.getUserName() + ") : " + user.getPassWord() );
               if (this.passWord.equals(user.getPassWord()) && this.userName.equals(user.getUserName())) {
                   return "SUCCESS";
               }
           }
           session.getTransaction().commit();
           session.close();

   
   总结一下查询的步骤:

   1. 注册
   2. 创建会话工厂
   3. 会话工厂生产会话
   4. 创建查询语句
   5. 会话执行查询语句
   6. 获取结果