Hibernate实战——定制SQL

系统管理员 2021-07-24 14:22 421阅读 0赞

**一 配置文件**

<?xml version="1.0" encoding="GBK"?>
    
    <!DOCTYPE hibernate-configuration PUBLIC
         "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
         "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
    
    <hibernate-configuration>
         <session-factory>
               
               <property  name="connection.driver_class">com.mysql.jdbc.Driver</property>
               
               <property  name="connection.url">jdbc:mysql://localhost/hibernate</property>
               
               <property name="connection.username">root</property>
               
               <property name="connection.password">32147</property>
               
               <property  name="hibernate.c3p0.max_size">20</property>
               
               <property name="hibernate.c3p0.min_size">1</property>
               
               <property  name="hibernate.c3p0.timeout">5000</property>
               
               <property  name="hibernate.c3p0.max_statements">100</property>
               <property  name="hibernate.c3p0.idle_test_period">3000</property>
               <property  name="hibernate.c3p0.acquire_increment">2</property>
               <property  name="hibernate.c3p0.validate">true</property>
               
               <property  name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
               
               <property name="hbm2ddl.auto">update</property>
               
               <property name="show_sql">true</property>
               
               <property name="hibernate.format_sql">true</property>
               
               <mapping class="org.crazyit.app.domain.News"/>
         </session-factory>
    </hibernate-configuration>

**二 PO**

package org.crazyit.app.domain;
    
    import javax.persistence.*;
    import org.hibernate.annotations.SQLInsert;
    import org.hibernate.annotations.SQLUpdate;
    import org.hibernate.annotations.SQLDelete;
    import org.hibernate.annotations.SQLDeleteAll;
    import org.hibernate.annotations.SQLDeleteAll;
    import org.hibernate.annotations.Loader;
    
    // 定制insert的SQL语句
    @SQLInsert(sql="insert into news_inf(content , title) values(upper(?), ?)")
    // 定制update的SQL语句
    @SQLUpdate(sql="update news_inf set content=upper(?), title=? where news_id=?")
    // 定制delete的SQL语句
    @SQLDelete(sql="delete from news_inf where news_id=?")
    // 定制删除所有实体的SQL语句
    @SQLDeleteAll(sql="delete from news_inf")
    // 指定使用news_loader命名查询作为定制查询的查询语句
    @Loader(namedQuery = "news_loader")
    // 定义一个命名SQL查询
    @NamedNativeQuery(name="news_loader"
        , query="select news_id , concat('===' , concat(title , '===')) as title"
            + " , content from news_inf n where news_id=?"
        , resultClass = News.class)
    @Entity
    @Table(name="news_inf")
    public class News
    {
        @Id @Column(name="news_id")
        @GeneratedValue(strategy=GenerationType.IDENTITY)
        private Integer id;
        private String title;
        private String content;
    
        // id的setter和getter方法
        public void setId(Integer id)
        {
            this.id = id;
        }
        public Integer getId()
        {
            return this.id;
        }
    
        // title的setter和getter方法
        public void setTitle(String title)
        {
            this.title = title;
        }
        public String getTitle()
        {
            return this.title;
        }
    
        // content的setter和getter方法
        public void setContent(String content)
        {
            this.content = content;
        }
        public String getContent()
        {
            return this.content;
        }
    
    }

**三 测试**

package lee;
    
    import org.hibernate.*;
    import org.hibernate.cfg.*;
    import org.hibernate.service.*;
    import org.hibernate.boot.registry.*;
    
    import org.crazyit.app.domain.*;
    
    public class NewsManager
    {
        public static void main(String[] args) throws Exception
        {
            // 实例化Configuration，这行代码默认加载hibernate.cfg.xml文件
            Configuration conf = new Configuration().configure();
            // 以Configuration实例创建SessionFactory实例
            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
                .applySettings(conf.getProperties()).build();
            SessionFactory sf = conf.buildSessionFactory(serviceRegistry);
            // 实例化Session
            Session sess = sf.openSession();
            // 开始事务
            Transaction tx = sess.beginTransaction();
            // 创建消息实例
            News n = new News();
            // 设置消息标题和消息内容
            n.setTitle("疯狂Java联盟成立了");
            n.setContent("adcb");
            // 保存消息
            sess.save(n);
            News n2 = (News)sess.get(News.class, 1);
            System.out.println(n2.getTitle());
            n2.setContent("aaaaaaaa");
            // 提交事务
            tx.commit();
            // 关闭Session
            sess.close();
        }
    }

**四 测试结果**

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