我使用JPA和Hibernate进行基本的继承层次结构设置，如下所示：
@Entity
@Table(uniqueConstraints=@UniqueConstraint(columnNames="email"))
@Inheritance(strategy = InheritanceType.JOINED)
public class User {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;
protected String firstName;
protected String surname;
protected String email;
protected String organization;
...
}
使用像这样的子类
@Entity
@PrimaryKeyJoinColumn(name="UserId", referencedColumnName="id")
public class Coach extends User{
public Coach(){
}
}
这将为Players和其他派生子类创建一个Base User表和一个表，但现在我无法对Coach实体执行EJQ-QL查询。我试图通过以下方式返回单元测试中的教练列表：
public List<Coach> getCoachByName(String firstName) {
return getJpaTemplate().find("select c from Coach c where c.firstName='"+firstName+"'");
}
但是我得到了GenericJDBC异常。
有什么建议吗？
这是请求的堆栈跟踪：
org.springframework.orm.hibernate3.HibernateJdbcException: JDBC exception on Hibernate data access: SQLException for SQL [select coach0_.UserId as id0_, coach0_1_.firstName as firstName0_, coach0_1_.surname as surname0_, coach0_1_.email as email0_, coach0_1_.organization as organiza5_0_, coach0_1_.hashedPassword as hashedPa6_0_, coach0_1_.confirmedRegistration as confirme7_0_ from Coach coach0_ inner join User coach0_1_ on coach0_.UserId=coach0_1_.id]; SQL state [3D000]; error code [1046]; could not execute query; nested exception is org.hibernate.exception.GenericJDBCException: could not execute query
at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:642)
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:95)
at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:212)
at org.springframework.orm.jpa.JpaAccessor.translateIfNecessary(JpaAccessor.java:152)
at org.springframework.orm.jpa.JpaTemplate.execute(JpaTemplate.java:189)
at org.springframework.orm.jpa.JpaTemplate.executeFind(JpaTemplate.java:151)
at org.springframework.orm.jpa.JpaTemplate.find(JpaTemplate.java:311)
at org.springframework.orm.jpa.JpaTemplate.find(JpaTemplate.java:307)
at com.playermetrics.dao.impl.CoachDaoImpl.getCoachByName(CoachDaoImpl.java:25)
at com.playermetrics.entities.CoachDaoTest.testSaveCoach(CoachDaoTest.java:43)
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:616)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at org.springframework.test.ConditionalTestCase.runBare(ConditionalTestCase.java:76)
at org.springframework.test.annotation.AbstractAnnotationAwareTransactionalTests.access$001(AbstractAnnotationAwareTransactionalTests.java:71)
at org.springframework.test.annotation.AbstractAnnotationAwareTransactionalTests$1.run(AbstractAnnotationAwareTransactionalTests.java:175)
at org.springframework.test.annotation.AbstractAnnotationAwareTransactionalTests.runTest(AbstractAnnotationAwareTransactionalTests.java:283)
at org.springframework.test.annotation.AbstractAnnotationAwareTransactionalTests.runTestTimed(AbstractAnnotationAwareTransactionalTests.java:254)
at org.springframework.test.annotation.AbstractAnnotationAwareTransactionalTests.runBare(AbstractAnnotationAwareTransactionalTests.java:172)
at org.springframework.test.jpa.AbstractJpaTests.runBare(AbstractJpaTests.java:174)
at org.springframework.test.jpa.AbstractJpaTests.runBare(AbstractJpaTests.java:255)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.hibernate.exception.GenericJDBCException: could not execute query
at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:103)
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:91)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.loader.Loader.doList(Loader.java:2214)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2095)
at org.hibernate.loader.Loader.list(Loader.java:2090)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:388)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:338)
at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:172)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1121)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:64)
at org.springframework.orm.jpa.JpaTemplate$9.doInJpa(JpaTemplate.java:319)
at org.springframework.orm.jpa.JpaTemplate.execute(JpaTemplate.java:184)
... 31 more
Caused by: java.sql.SQLException: No database selected
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1073)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3597)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3529)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1990)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2151)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2625)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2119)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2281)
at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:186)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1778)
at org.hibernate.loader.Loader.doQuery(Loader.java:662)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
at org.hibernate.loader.Loader.doList(Loader.java:2211)
... 41 more