Hibernate不能生成id(Hibernate can't generate id)

 我在我的IntelliJ IDEA上创建了一个新项目，使用hibernate（+ hibernate entitymanager）5，hsqldb 1.8（仅用于测试）以及junit 4。 
 
 我有我的测试课 
 
 
 
 UserRoundRelationsTest 
 
 
EntityManagerFactory emf;
EntityManager em;

Date currentDate;
User user;
Round round1;
Round round2;
 
 还有一些@After和@Before方法： 
 
@Before
public void saveDummyUserAndTwoDummyRounds() {

    emf = Persistence.createEntityManagerFactory("testPersistence");
    em = emf.createEntityManager(); // Retrieve an application managed entity manager

    currentDate = new Date();
    user = new User.UserBuilder("alias").fullName("Full Name").phoneNumber("Phone Number").height(100).weight(100).birthDate(currentDate).build();

    round1 = new Round(new GameMode(1, ButtonTargetStrategy.RANDOM, ButtonSkipStrategy.SKIP_ON_MISTAKE));
    round2 = new Round(new GameMode(2, ButtonTargetStrategy.RANDOM, ButtonSkipStrategy.SKIP_ON_MISTAKE));

    round1.setUser(user);
    round2.setUser(user);

    HashSet<Round> rounds = new HashSet<Round>(2);
    rounds.add(round1);
    rounds.add(round2);

    em.getTransaction().begin();

    user.setRounds(rounds);

    em.persist(user);
    em.persist(round1);
    em.persist(round2);

    em.flush();
    em.getTransaction().commit();
}
 
 和 
 
@After
public void deleteData() {

    em.remove(user);
    em.remove(round2);
    em.remove(round2);

    em.getTransaction().commit();

    em.close();
    emf.close();
}
 
 首先，当我尝试运行测试时，hibernate无法找到User和Round类的表以及它们依赖的所有内容（例如，称为ButtonPress的类）。 我认为这是由于我在persistence.xml中配置的自动创建 - 删除 
 
<persistence-unit name="testPersistence">
    <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>

    <class>com.carloworks.model.User</class>
    <class>com.carloworks.model.Round</class>
    <class>com.carloworks.model.ButtonPress</class>
    <properties>
        <!--<property name="hibernate.archive.autodetection" value="class,hbm"></property>-->

        <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"></property>
        <property name="hibernate.show_sql" value="true"></property>
        <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"></property>
        <property name="hibernate.connection.username" value="sa"></property>
        <property name="hibernate.connection.password" value=""></property>
        <property name="hibernate.connection.url"
                  value="jdbc:hsqldb:mem:buttonMasherModelsTestDb;MV_STORE=FALSE;MVCC=FALSE"></property>
        <!--<property name="hibernate.default_schema" value="buttonMasherModelsTestDb"/>-->
        <property name="hibernate.hbm2ddl.auto" value="create-drop"></property>
    </properties>
</persistence-unit>
 
 进一步向下滚动错误日志，我也在这一行发生错误： 
 
em.persist(user);
 
 
 
 
  
 空标识符（加'不支持此函数'/'GenericJDBCException：无法准备语句'）。 
 
 
 
 
 我做错了什么？ 
 
 该项目也在Github上提供 
 
 完整的错误日志 

I've created a new project on my IntelliJ IDEA, using hibernate (+ hibernate entitymanager) 5, hsqldb 1.8 (for testing only), as well as junit 4.
 
I've got my test class 
 
 
 
UserRoundRelationsTest
 
 
EntityManagerFactory emf;
EntityManager em;

Date currentDate;
User user;
Round round1;
Round round2;
 
And some @After and @Before methods:
 
@Before
public void saveDummyUserAndTwoDummyRounds() {

    emf = Persistence.createEntityManagerFactory("testPersistence");
    em = emf.createEntityManager(); // Retrieve an application managed entity manager

    currentDate = new Date();
    user = new User.UserBuilder("alias").fullName("Full Name").phoneNumber("Phone Number").height(100).weight(100).birthDate(currentDate).build();

    round1 = new Round(new GameMode(1, ButtonTargetStrategy.RANDOM, ButtonSkipStrategy.SKIP_ON_MISTAKE));
    round2 = new Round(new GameMode(2, ButtonTargetStrategy.RANDOM, ButtonSkipStrategy.SKIP_ON_MISTAKE));

    round1.setUser(user);
    round2.setUser(user);

    HashSet<Round> rounds = new HashSet<Round>(2);
    rounds.add(round1);
    rounds.add(round2);

    em.getTransaction().begin();

    user.setRounds(rounds);

    em.persist(user);
    em.persist(round1);
    em.persist(round2);

    em.flush();
    em.getTransaction().commit();
}
 
and
 
@After
public void deleteData() {

    em.remove(user);
    em.remove(round2);
    em.remove(round2);

    em.getTransaction().commit();

    em.close();
    emf.close();
}
 
Firstly, when I try to run the test, hibernate can't find the tables for User and Round classes, as well as everything they are dependent on (a class called ButtonPress for example). I assume this happens due to the automatic create-drop I have configured at my persistence.xml 
 
<persistence-unit name="testPersistence">
    <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>

    <class>com.carloworks.model.User</class>
    <class>com.carloworks.model.Round</class>
    <class>com.carloworks.model.ButtonPress</class>
    <properties>
        <!--<property name="hibernate.archive.autodetection" value="class,hbm"></property>-->

        <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"></property>
        <property name="hibernate.show_sql" value="true"></property>
        <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"></property>
        <property name="hibernate.connection.username" value="sa"></property>
        <property name="hibernate.connection.password" value=""></property>
        <property name="hibernate.connection.url"
                  value="jdbc:hsqldb:mem:buttonMasherModelsTestDb;MV_STORE=FALSE;MVCC=FALSE"></property>
        <!--<property name="hibernate.default_schema" value="buttonMasherModelsTestDb"/>-->
        <property name="hibernate.hbm2ddl.auto" value="create-drop"></property>
    </properties>
</persistence-unit>
 
Scrolling further down the error logs, I also get an error at this line:
 
em.persist(user);
 
 
 
 
  
null identifier (plus 'This function is not supported'/'GenericJDBCException: could not prepare statement').
 
 
 
 
What did I do wrong?
 
The project is also available on Github
 
Full Error Log

原文：https://stackoverflow.com/questions/41063083