通过hibernate访问postgreSQL的搭建过程

2024年4月20日 118次阅读 来源: PostgreSQL
  1. 环境:win7,Intellij IDEA
  2. postgreSQL的安装:
    1. 安装包下载:https://www.postgresql.org/download/　去官网下载postgresql-9.1.3-1-windows.exe（46M）
    2. 傻瓜式安装,跟着安装引导走,一路next,用户名默认为 postgres,密码*****,端口默认5432
    3. 启动服务,打开services.msc,如果postgre没有启动则手动启动
  3. postgreSQL客户的工具的安装:目前有多种客户工具,我用的是navicat for postgreSQL,去官网下载https://www.navicat.com/download/navicat-for-postgresql
    1. 解压压缩包,点击navicat.ext启动
    2. 双击连接->填写用户名,密码,端口,连接名,创建连接
    3. 右键点击连接名称,创建数据库
    4. 创建模式,(postgre的数据结构多了一层模式的结构,数据库>模式>表>字段),数据库创建时有默认的模式为public,右键数据库名,创建模式myschema
    5. 创建表,右键表,创建表,填写字段(user_id,username,password);
  4. 搭建hibernate环境:
    1. 用Intellij 新建javaWeb项目
    2. 引入jar包:
      1. 　　hibernate jar包 在pom.xml写依赖:
        <!--hibernate--> <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core --> <dependency>  <groupId>org.hibernate</groupId>  <artifactId>hibernate-core</artifactId>  <version>5.1.2.Final</version> </dependency>
      2. 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>
    3. 配置hibernate配置文件,项目由maven管理,在resources目录下加入hibernate.cfg.xml文件,该配置文件主要记录了数据库的有户名,ip,密码,端口,所用jdbc驱动等信息内容如下:
      <?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>

       

  5. hibernate的查询语句,hibernate的操作有两种1.xml文件配置2.注解,这里用的是注解法,图个方便.
    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

 

　　

 

    原文作者：PostgreSQL
    原文地址: https://www.cnblogs.com/XD-thinker/p/6722023.html
    本文转自网络文章，转载此文章仅为分享知识，如有侵权，请联系博主进行删除。
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