java.lang.IllegalArgumentException异常 数据库别名问题

 java.lang.IllegalArgumentException: org.hibernate.hql.internal.ast.QuerySyntaxException: Path expected for join! [from com.tao.pojo.Student  inner join clazz]
     at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:133)
     at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:157)
     at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:164)
     at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:670)
     at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:686)
     at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:103)
     at com.tao.test.StudentTest.test001(StudentTest.java:47)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     at java.lang.reflect.Method.invoke(Method.java:498)
     at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
     at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
     at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
     at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
     at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
     at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
     at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
     at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
     at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
     at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
     at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
     at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
     at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
     at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
     at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
     at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
     at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
 Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: Path expected for join! [from com.tao.pojo.Student  inner join clazz]
     at org.hibernate.hql.internal.ast.QuerySyntaxException.convert(QuerySyntaxException.java:74)
     at org.hibernate.hql.internal.ast.ErrorCounter.throwQueryException(ErrorCounter.java:91)
     at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:272)
     at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:189)
     at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:141)
     at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:115)
     at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:77)
     at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:153)
     at org.hibernate.internal.AbstractSharedSessionContract.getQueryPlan(AbstractSharedSessionContract.java:553)
     at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:662)
     ... 28 more

 org.hibernate.TransactionException: Transaction was marked for rollback only; cannot commit
     at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:228)
     at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:68)
     at com.tao.test.StudentTest.testAfter(StudentTest.java:32)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     at java.lang.reflect.Method.invoke(Method.java:498)
     at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
     at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
     at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
     at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:33)
     at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
     at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
     at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
     at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
     at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
     at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
     at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
     at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
     at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
     at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
     at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

这里这个错误是因为类Student没有起别名，给个别名就对了
@Test
    public void test001() {
        Query<Object[]> query = session.createQuery("from Student inner join clazz", Object[].class);
        List<Object[]> list = query.list();
        for (Object[] oo : list) {
            System.out.println(oo[0]+","+oo[1]);
        }
    }
正确写法（这样写最后返回的就是Object类型的数组）
　　@Test
    public void test001() {
        Query<Object[]> query = session.createQuery("from Student s inner join s.clazz", Object[].class);
        List<Object[]> list = query.list();
        for (Object[] oo : list) {
            System.out.println(oo[0]+","+oo[1]);
        }
    }
第一行末尾已经指出，
Path expected for join! [from com.tao.pojo.Student inner join clazz]