我将Apache Derby与Hibernate一起用于测试项目的一个模型类（它们的 equals ， hashCode
实现，查询等）。MySQL被用作生产数据库。我选择Derby而不是HSQLDB，因为我经历了与Hibernate和HSQLDB的一些不兼容，这意味着，鉴于我的实体（它们的名称，架构，键）及其关系，Hibernate无法在HSQLDB中创建我的数据库架构，而德比
就是说，也许我搞砸了；不兼容问题也可以得到解决。

无论如何，这就是我在测试中使用的东西（我已经修改了我的代码，pom.xml以便将Derby包含为 运行时
依赖项并运行一个测试，以确保它可以正常工作）。

pom.xml

<dependencies>                                      
  ...                               
  <dependency>                                      
    <groupId>org.hibernate</groupId>                
    <artifactId>hibernate-entitymanager</artifactId>
    <version>3.6.8.Final</version>                  
  </dependency>                                     
  <dependency>                                      
    <groupId>org.apache.derby</groupId>             
    <artifactId>derby</artifactId>                  
    <version>10.8.2.2</version>                     
    <scope>runtime</scope>                          
  </dependency>                                     
  <!-- 
     an slf4j implementation is needed by
     hibernate so that it could log its *stuff*
  -->
  <dependency>                                      
    <groupId>org.slf4j</groupId>                    
    <artifactId>slf4j-simple</artifactId>           
    <version>1.6.4</version>                        
    <scope>runtime</scope>                          
  </dependency>                                     
  ...                             
</dependencies>

persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
  version="2.0">
  <persistence-unit name="test">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <class>Test</class>
    <properties>
      <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver"/>
      <!--
        if you don't have a database already created
        append ;create=true to end of the jdbc url
      -->
      <property name="javax.persistence.jdbc.url" value="jdbc:derby:test"/>
      <property name="javax.persistence.jdbc.user" value="root"/>
      <property name="javax.persistence.jdbc.password" value="root"/>
      <!--  
        if you just created the database, maybe
        you want hibernate to create a schema for you

        <property name="hibernate.hbm2ddl.auto" value="create"/> 
      -->
    </properties>
  </persistence-unit>
</persistence>

Test 实体

@Entity
@Table(name = "test")
public class Test {

  @Id
  public int id;

  @Basic
  public String data;
}

测试

EntityManagerFactory emf = Persistence.createEntityManagerFactory("test");  
EntityManager em = emf.createEntityManager();                               
EntityTransaction tx = em.getTransaction();

Test test = em.find(Test.class, 1);                                         
if (test == null) {                                                         
  test = new Test();                                                        
  test.id = 1;                                                              
  test.data = "a";

  tx.begin();                                                               
  em.persist(test);                                                         
  tx.commit();                                                              
}

System.out.format("Test{id=%s, data=%s}\n", test.id, test.data);

em.close();                                                                 
emf.close();