在 Hibernate 5 中未使用 hbm2ddl.auto=update 创建表

Posted 2023-02-24

【中文标题】在 Hibernate 5 中未使用 hbm2ddl.auto=update 创建表

【英文标题】：Table not created with hbm2ddl.auto=update in Hibernate 5

【发布时间】：2016-01-31 16:18:07

【问题描述】：

数据库表不是由hibernate-cfg.xml 中的<property name="hbm2ddl.auto">update</property> 设置自动创建的，具有以下组合：

Java 8 + Tomcat 8 + MySQL + Hibernate 5

Java 版本：

java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)

mysql 版本：

mysql  Ver 14.14 Distrib 5.6.16, for osx10.7 (x86_64) using  EditLine wrapper

Tomcat 版本：

apache-tomcat-8.0.22

pom.xml sn-ps:

<dependency>
  <groupId>org.eclipse.persistence</groupId>
  <artifactId>javax.persistence</artifactId>
  <version>2.1.0</version>
</dependency>
<dependency>
  <groupId>javax.transaction</groupId>
  <artifactId>jta</artifactId>
  <version>1.1</version>
</dependency>
<dependency>
  <groupId>org.hibernate.javax.persistence</groupId>
  <artifactId>hibernate-jpa-2.1-api</artifactId>
  <version>1.0.0.Final</version>
</dependency>
<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-core</artifactId>
  <version>5.0.3.Final</version>
</dependency>
<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-entitymanager</artifactId>
  <version>5.0.3.Final</version>
</dependency>
<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-c3p0</artifactId>
  <version>5.0.3.Final</version>
</dependency>

实体类：

package com.test.entity;

import java.util.Date;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;

import org.hibernate.annotations.GenericGenerator;

@Entity
@Table( name = "EVENTS" )
public class Event 
    @Id
    @GeneratedValue(generator="increment")
    @GenericGenerator(name="increment", strategy = "increment")
    private Long id;

    private String title;

    @Temporal(TemporalType.TIMESTAMP)
    @Column(name = "EVENT_DATE")
    private Date date;

    public Event() 

    public Long getId()  return id; 
    private void setId(Long id)  this.id = id; 
    public Date getDate()  return date; 
    public void setDate(Date date)  this.date = date; 
    public String getTitle()  return title; 
    public void setTitle(String title)  this.title = title; 

休眠SessionFactory初始化：

String resource = "hibernate.cfg.xml";
Configuration configuration = new Configuration();
configuration.configure(resource);
ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
SessionFactory sessionFactoryCore = configuration.buildSessionFactory(serviceRegistry);

hibernate.cfg.xml：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC 
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN" 
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> 
<hibernate-configuration>
  <session-factory>
    <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="connection.url">jdbc:mysql://localhost:3306/test</property>
    <property name="connection.username">mysqluser</property>
    <property name="connection.password">******</property>
    <property name="hbm2ddl.auto">update</property>
    <property name="hibernate.max_fetch_depth">3</property>
    <mapping class="com.test.entity.Event" />
  </session-factory>
</hibernate-configuration>

但是，该表是在 MySQL 数据库中创建的，具有以下组合：

Java 8 + Tomcat 8 + MySQL + Hibernate 4

一切都和上面一样，除了在 pom.xml 中，我使用的是 hibernate 4 而不是 5：

<dependency>
  <groupId>org.eclipse.persistence</groupId>
  <artifactId>javax.persistence</artifactId>
  <version>2.1.0</version>
</dependency>
<dependency>
  <groupId>javax.transaction</groupId>
  <artifactId>jta</artifactId>
  <version>1.1</version>
</dependency>
<dependency>
  <groupId>org.hibernate.javax.persistence</groupId>
  <artifactId>hibernate-jpa-2.1-api</artifactId>
  <version>1.0.0.Final</version>
</dependency>
<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-core</artifactId>
  <version>4.3.11.Final</version>
</dependency>
<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-entitymanager</artifactId>
  <version>4.3.11.Final</version>
</dependency>
<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-c3p0</artifactId>
  <version>4.3.11.Final</version>
</dependency>

我在 Hibernate 5 中缺少什么？

【参考方案1】：

我们在升级到 Hibernate 5.x 后遇到了类似的问题，通过将 dialect 更改为 org.hibernate.dialect.MySQL5Dialect 解决了这个问题。

【参考方案2】：

在您的休眠配置文件中添加<property name="javax.persistence.schema-generation.database.action">create</property>。

【讨论】：

一些解释会大大提高答案的质量，帮助以后可能遇到类似问题的其他用户请花点时间阅读帮助页面***.com/help/how-to-answer

【参考方案3】：

在 sessionFactoryInitialisation 中尝试类似的操作：

StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder().configure(configFile).build();       
Metadata metadata =new MetadataSources(standardRegistry).getMetadataBuilder().build();  
sessionFactory = metadata.getSessionFactoryBuilder().build();
return sessionFactory;

【讨论】：

如何解决自动创建问题？