Question

<property name="hbm2ddl.auto">update</property>中的hibernate-cfg.xml设置自动创建数据库表 NOT ，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片段：

<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; }
}

Hibernate 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中：

<?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>

HOWEVER ，表格已创建到MySQL数据库中，具有以下组合：

Java 8 + Tomcat 8 + MySQL + Hibernate 4

除了在pom.xml中之外，所有内容都与上面相同，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>

Hibernate 5中缺少什么？

Answer 1

升级到Hibernate 5.x后我们遇到了类似的问题，这可以通过将 dialect 更改为 org.hibernate.dialect.MySQL5Dialect 来解决。

Answer 2

在 sessionFactoryInitialisation ：

中尝试类似的方法

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

Answer 3

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

Answer 4

正确的属性名称为：hibernate.hbm2ddl.auto

文档：https://docs.jboss.org/hibernate/orm/5.0/manual/en-US/html/ch03.html#configuration-optional

在hibernate 5中没有使用hbm2ddl.auto = update创建的表

4 个答案: