title: Problems mapping UUID in JPA/hibernate
body: <p>According to the documentation, hibernate 3.6 should have support for the java.util.UUID type. But when I map it like:</p>
  
  <pre><code>@Id protected UUID uuid;
  </code></pre>
  
  <p>I get the following exception:</p>
  
  <pre><code>Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [test-applicationContext.xml]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: persistenceUnit] Unable to build EntityManagerFactory
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1420) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.findDefaultEntityManagerFactory(PersistenceAnnotationBeanPostProcessor.java:529) ~[spring-orm-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.findEntityManagerFactory(PersistenceAnnotationBeanPostProcessor.java:495) ~[spring-orm-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor$PersistenceElement.resolveEntityManager(PersistenceAnnotationBeanPostProcessor.java:656) ~[spring-orm-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor$PersistenceElement.getResourceToInject(PersistenceAnnotationBeanPostProcessor.java:629) ~[spring-orm-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:147) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:84) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.postProcessPropertyValues(PersistenceAnnotationBeanPostProcessor.java:338) ~[spring-orm-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      ... 51 common frames omitted
  Caused by: javax.persistence.PersistenceException: [PersistenceUnit: persistenceUnit] Unable to build EntityManagerFactory
      at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:911) ~[hibernate-entitymanager-3.6.0.Final.jar:3.6.0.Final]
      at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:74) ~[hibernate-entitymanager-3.6.0.Final.jar:3.6.0.Final]
      at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:225) ~[spring-orm-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:308) ~[spring-orm-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1477) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417) ~[spring-beans-3.0.5.RELEASE.jar:3.0.5.RELEASE]
      ... 64 common frames omitted
  Caused by: org.hibernate.MappingException: No Dialect mapping for JDBC type: -2
      at org.hibernate.dialect.TypeNames.get(TypeNames.java:78) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
      at org.hibernate.dialect.TypeNames.get(TypeNames.java:103) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
      at org.hibernate.dialect.Dialect.getTypeName(Dialect.java:249) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
      at org.hibernate.mapping.Column.getSqlType(Column.java:208) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
      at org.hibernate.mapping.Table.sqlTemporaryTableCreateString(Table.java:371) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
      at org.hibernate.mapping.PersistentClass.prepareTemporaryTables(PersistentClass.java:765) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
      at org.hibernate.impl.SessionFactoryImpl.&lt;init&gt;(SessionFactoryImpl.java:270) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
      at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1842) ~[hibernate-core-3.6.0.Final.jar:3.6.0.Final]
      at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:902) ~[hibernate-entitymanager-3.6.0.Final.jar:3.6.0.Final]
      ... 69 common frames omitted
  </code></pre>
  
  <p>I know questions with stack traces are not very popular but this is a very hibernate-specific problem and I have been unable to find anything on google :)</p>
  
  <p>Thanks</p>