【发布时间】：2019-05-27 15:14:54
【问题描述】：
我在 MySQL 中使用了 LIKE 语句，但不知何故，它的行为超出了我的预期。它给了我“java.sql.SQLException：在 mysql 中的结果集结束后”我无法弄清楚发生了什么。
我试着查了一下，有人说 while(rs.next()){...} 会修复它，但它对我不起作用。
public ArrayList<Person> lookUp(String keywordContent) throws SQLException {
// Four different string query to look for all fields
String query1 = ("Select * from personinfo where FirstN like ?");
String query2 = ("Select * from personinfo where MiddleI like ?");
String query3 = ("Select * from personinfo where LastN like ?");
String query4 = ("Select * from personinfo where studentId like ?");
// Four result set to get each query result
pst = con.prepareStatement(query1);
pst.setString(1, "%"+keywordContent+"%");
ResultSet rs1 = pst.executeQuery();
//--
pst = con.prepareStatement(query2);
pst.setString(1, "%"+keywordContent+"%");
ResultSet rs2 = pst.executeQuery();
//--
pst = con.prepareStatement(query3);
pst.setString(1, "%"+keywordContent+"%");
ResultSet rs3 = pst.executeQuery();
//--
pst = con.prepareStatement(query4);
pst.setString(1, "%"+keywordContent+"%");
ResultSet rs4 = pst.executeQuery();
ArrayList<Person> peopleAL = new ArrayList<>();
while (rs1.next()) {
peopleAL.add(new Person(rs.getString(1), rs.getString(2), rs.getString(3), rs.getString(4)));
}
while (rs2.next()) {
peopleAL.add(new Person(rs.getString(1), rs.getString(2), rs.getString(3), rs.getString(4)));
}
while (rs3.next()) {
peopleAL.add(new Person(rs.getString(1), rs.getString(2), rs.getString(3), rs.getString(4)));
}
while (rs4.next()) {
peopleAL.add(new Person(rs.getString(1), rs.getString(2), rs.getString(3), rs.getString(4)));
}
return peopleAL;
}
这是我的例外：
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8411)
at javafx.scene.control.Button.fire(Button.java:185)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.keyReleased(ButtonBehavior.java:136)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.callAction(ButtonBehavior.java:106)
at com.sun.javafx.scene.control.behavior.BehaviorBase.callActionForEvent(BehaviorBase.java:218)
at com.sun.javafx.scene.control.behavior.BehaviorBase.lambda$new$74(BehaviorBase.java:135)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$KeyHandler.process(Scene.java:3964)
at javafx.scene.Scene$KeyHandler.access$1800(Scene.java:3910)
at javafx.scene.Scene.impl_processKeyEvent(Scene.java:2040)
at javafx.scene.Scene$ScenePeerListener.keyEvent(Scene.java:2501)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:217)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:149)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleKeyEvent$352(GlassViewEventHandler.java:248)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(GlassViewEventHandler.java:247)
at com.sun.glass.ui.View.handleKeyEvent(View.java:546)
at com.sun.glass.ui.View.notifyKey(View.java:966)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771)
... 49 more
Caused by: java.sql.SQLException: After end of result set
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:129)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63)
at com.mysql.cj.jdbc.result.ResultSetImpl.checkRowPos(ResultSetImpl.java:516)
at com.mysql.cj.jdbc.result.ResultSetImpl.getString(ResultSetImpl.java:944)
at bookswapakm.DBConn.lookUp(DBConn.java:322)
at bookswapakm.FXMLDocumentController.lookUp(FXMLDocumentController.java:476)
... 59 more
我希望它查找包含我通过参数传递的关键字的所有数据。
【问题讨论】：
-
您在
rs1、rs2、rs3和rs4上有循环，但随后您尝试从rs获取数据。它是在哪里定义的？ -
在你的 sql 中使用 OR 三次（4 个谓词）肯定会更简单吗？
Select * from personinfo where FirstN like ? OR MiddleI like ? OR LastN like ? OR studentId like ? -
我相信对同一个
Statement执行另一个查询会关闭前一个ResultSet。在获得下一个之前，您应该阅读每个ResultSet。 -
@Slaw 是的，你是对的
-
@Mureinik 这是一个很好的观点， rs 是一个全局结果集，我想我已经弄清楚了原因。我认为只是我忘记将数字放入 rs 中，例如 1、2、3、4。谢谢