这是我第一次使用Hibernate,当我在一个循环中插入多行时,hibernate会为每一行插入以下内容

Hibernate: select nextval ('hibernate_sequence')

在它为循环中的所有数据执行此操作后,它开始插入数据

Hibernate: insert into user_data (age, location, sent_count, user_id, username, id) values (?, ?, ?, ?, ?, ?)

这是hibernate总是如何运作的？数据库是否无法处理序列？我觉得这真的会减慢插入行的过程.我正在使用PostgreSQL作为我的数据库.

这是我的相关代码

用户数据

@Entity

@Table(name = "user_data")

public class UserData

{

@Id @GeneratedValue

@Column(name = "id")

private int id;

@Column(name = "user_id")

private String userid;

@Column(name = "username")

private String username;

@Column(name = "age")

private int age;

@Column(name = "location")

private int location;

@Column(name = "sent_count")

private int sentCount;

public int getId()

{

return id;

}

public void setId(int id)

{

this.id = id;

}

public String getUserid()

{

return userid;

}

public void setUserid(String userid)

{

this.userid = userid;

}

public String getUsername()

{

return username;

}

public void setUsername(String username)

{

this.username = username;

}

public int getAge()

{

return age;

}

public void setAge(int age)

{

this.age = age;

}

public int getLocation()

{

return location;

}

public void setLocation(int location)

{

this.location = location;

}

public int getSentCount()

{

return sentCount;

}

public void setSentCount(int sentCount)

{

this.sentCount = sentCount;

}

}

我的Hibernate助手类

public class HibernateUtil

{

static SessionFactory sessionFactory;

static ServiceRegistry serviceRegistry;

static

{

try

{

Configuration configuration = new Configuration();

configuration.setProperty("hibernate.temp.use_jdbc_metadata_defaults", "false");

configuration.configure();

serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();

sessionFactory = configuration.buildSessionFactory(serviceRegistry);

}

catch (Throwable ex)

{

// Make sure you log the exception, as it might be swallowed

System.err.println("Initial SessionFactory creation failed." + ex);

closeSessionFactory();

throw new ExceptionInInitializerError(ex);

}

}

public static SessionFactory getSessionFactory()

{

return sessionFactory;

}

public static void closeSessionFactory()

{

sessionFactory.close();

}

}

以及插入行的相关部分

Session session = HibernateUtil.getSessionFactory().openSession();

session.beginTransaction();

for (String memberId : memberIds)

{

System.out.println(memberId);

UserData user = new UserData();

user.setUserid(memberId);

session.save(user);

}

session.getTransaction().commit();

session.close();

HibernateUtil.closeSessionFactory();