在尝试将字符串转换为日期以进行比较时，Hibernate会抛出
org.hibernate.exception.GenericJDBCException：无法执行查询
完整的堆栈跟踪：
javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: could not execute query
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1387)
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1315)
at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:255)
at com.callsystem.business.callFinder.findCustom(callFinder.java:215)
at com.callsystem.UI.searchCustomerCallsView$2.buttonClick(searchCustomerCallsView.java:99)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:508)
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:198)
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:161)
at com.vaadin.server.AbstractClientConnector.fireEvent(AbstractClientConnector.java:1008)
at com.vaadin.ui.Button.fireClick(Button.java:377)
at com.vaadin.ui.Button$1.click(Button.java:54)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:158)
at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:118)
at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:408)
at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:273)
at com.vaadin.server.communication.PushHandler$2.run(PushHandler.java:149)
at com.vaadin.server.communication.PushHandler.callWithUi(PushHandler.java:243)
at com.vaadin.server.communication.PushHandler.onMessage(PushHandler.java:503)
at com.vaadin.server.communication.PushAtmosphereHandler.onMessage(PushAtmosphereHandler.java:88)
at com.vaadin.server.communication.PushAtmosphereHandler.onRequest(PushAtmosphereHandler.java:78)
at org.atmosphere.cpr.AsynchronousProcessor.action(AsynchronousProcessor.java:199)
at org.atmosphere.cpr.AsynchronousProcessor.suspended(AsynchronousProcessor.java:107)
at org.atmosphere.container.TomcatWebSocketUtil.doService(TomcatWebSocketUtil.java:154)
at org.atmosphere.container.Tomcat7Servlet30SupportWithWebSocket.service(Tomcat7Servlet30SupportWithWebSocket.java:62)
at org.atmosphere.cpr.AtmosphereFramework.doCometSupport(AtmosphereFramework.java:2075)
at org.atmosphere.websocket.DefaultWebSocketProcessor.dispatch(DefaultWebSocketProcessor.java:571)
at org.atmosphere.websocket.DefaultWebSocketProcessor$3.run(DefaultWebSocketProcessor.java:333)
at org.atmosphere.util.VoidExecutorService.execute(VoidExecutorService.java:101)
at org.atmosphere.websocket.DefaultWebSocketProcessor.dispatch(DefaultWebSocketProcessor.java:328)
at org.atmosphere.websocket.DefaultWebSocketProcessor.invokeWebSocketProtocol(DefaultWebSocketProcessor.java:425)
at org.atmosphere.websocket.DefaultWebSocketProcessor.dispatchReader(DefaultWebSocketProcessor.java:795)
at org.atmosphere.websocket.DefaultWebSocketProcessor.invokeWebSocketProtocol(DefaultWebSocketProcessor.java:527)
at org.atmosphere.container.TomcatWebSocketHandler.onTextData(TomcatWebSocketHandler.java:104)
at org.apache.catalina.websocket.StreamInbound.doOnTextData(StreamInbound.java:190)
at org.apache.catalina.websocket.StreamInbound.onData(StreamInbound.java:138)
at org.apache.coyote.http11.upgrade.UpgradeProcessor.upgradeDispatch(UpgradeProcessor.java:88)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:599)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
at java.lang.Thread.run(Thread.java:662)
Caused by: org.hibernate.exception.GenericJDBCException: could not execute query
at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:140)
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:128)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.loader.Loader.doList(Loader.java:2545)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2276)
at org.hibernate.loader.Loader.list(Loader.java:2271)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:459)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:365)
at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1268)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:246)
... 46 more
Caused by: java.sql.SQLException: No database selected
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1086)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4237)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4169)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2617)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2778)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2834)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2156)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2313)
at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1953)
at org.hibernate.loader.Loader.doQuery(Loader.java:802)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:274)
at org.hibernate.loader.Loader.doList(Loader.java:2542)
... 54 more
使用的HQl语句：
String hql = "FROM CallSystemCustomerCallEntity WHERE str(refno) LIKE :refNo AND "
+ "customer LIKE :customer AND site LIKE :site AND faults LIKE :faults "
+ "AND detailedfaults LIKE :dfaults AND owner LIKE :owner "
+ "AND date(to_date(date, 'dd-MM-yy')) >= :sDate AND "
+ "date(to_date(date, 'dd-MM-yy')) <= :eDate ORDER BY refno asc";
创建查询：
List<CallSystemCustomerCallEntity> c = em.createQuery(hql).
setParameter("refNo", "%" + refNo + "%").setParameter("customer", "%" + customer + "%")
.setParameter("site", "%" + site + "%").setParameter("faults", "%" + faults + "%")
.setParameter("dfaults", "%" + dfaults + "%").setParameter("owner", "%" + owner + "%")
.setParameter("sDate",date1).setParameter("eDate", date2).getResultList();
有问题的数据库是MySQL数据库和我尝试的所有其他查询，但是包含日期参数会导致抛出此异常。
答案 0 :(得分：0)
猜测：你调用了to_date函数，但因为它不是一个hql函数，所以它按原样发送到数据库。 Mysql收到一个带有＆＃34; to_date＆＃34;的sql请求。函数，但mysql没有to_date函数（它具有Oracle特定功能，你必须使用STR_TO_DATE）。所以mysql将该函数作为当前数据库中的自定义函数进行搜索，但是抱怨没有选择数据库......
所以，删除to_date（和date（））并尝试使用STR_TO_DATE（参见https://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html）。
编辑：并使用来自hibernate的调试日志来查看发送到数据库的sql =＆gt; stacktrace显示异常来自数据库，使用sql可以测试针对数据库的查询：它有助于调试