JPA CONSOLE无法正常工作

Question

我正在尝试使用IntelliJ Idea的jpa控制台，但出现此错误

jpa-ql>从usuario中选择nombre

[2014-10-25 13:57:52] javax.persistence.PersistenceException: [PersistenceUnit: sigarep-persistence] Unable to build EntityManagerFactory
[2014-10-25 13:57:52] java.lang.RuntimeException: org.hibernate.HibernateException: Connection cannot be null when 'hibernate.dialect' not set
    at org.hibernate.service.jdbc.dialect.internal.DialectFactoryImpl.determineDialect(DialectFactoryImpl.java:97)
    at org.hibernate.service.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:67)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:174)
    at org.hibernate.service.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:75)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:159)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:131)
    at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:78)
    at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2293)
    at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2289)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1758)
    at org.hibernate.ejb.EntityManagerFactoryImpl.(EntityManagerFactoryImpl.java:96)
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:913)
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:898)
    at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:59)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:63)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:47)
    at com.intellij.jpa.remote.impl.JpaFacadeImpl.createEntityManagerFactory(JpaFacadeImpl.java:16)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322)
    at sun.rmi.transport.Transport$1.run(Transport.java:177)
    at sun.rmi.transport.Transport$1.run(Transport.java:174)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:556)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:811)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:670)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)

有人能帮我吗？

Answer 1

在使用为 JPA 2.1 配置的 persistance.xml 时，我遇到了类似的问题，如下所示：

<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
...
</persistance>

我发现的唯一解决方法是切换到 jpa 2.0

<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">
...
</persistance>