[Microsoft][ODBC SQL Server Driver][SQL Server]对象名 'tb2' 无效。 ???

aitilang 2009-06-23 09:56:49

出现错误
java.sql.SQLException: [Microsoft][ODBC SQL Server Driver][SQL Server]对象名 'tb2' 无效。
但是数据库连接成功，该表tb2也在查看器中可以查到，详细代码如下：

import java.awt.*;
import java.net.*;
import java.applet.*;
import java.sql.*;

public class BackgroundDemo extends Applet //implements WindowListener
{
Image bg;
Button bt;
URL pos;
String output;

public void init()
{
this.setBackground(Color.LIGHT_GRAY );
setSize(400,300);

}

public void start(){
System.out.println("====SSSSSSSSSSSSSBBBB111====");
System.out.println(output);
System.out.println("====SSSSSSSSSSSSSEEEE111====");
myPrint(output);
System.out.println("====SSSSSSSSSSSSSBBBB2222====");
System.out.println(output);
System.out.println("====SSSSSSSSSSSSSEEEE2222====");
}

public void paint(Graphics g){
System.out.println("====XXXXXXXXXXXX====");
g.drawRect(0, 0, size().width -1, size().height-1);
g.drawString(output, 10, 10);
}
public void myPrint(String s){

String connectionUrl = "jdbc:odbc:DNS";
Connection con = null;
Statement stmt = null;
ResultSet rs = null;

try {

Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
con = DriverManager.getConnection(connectionUrl);
System.out.println("数据库联接成功!!");

stmt = con.createStatement();

String query = "SELECT * FROM tb2";

rs = stmt.executeQuery( query );

System.out.println();
System.out.println("sheet1:");
System.out.print(" 学号 " );
System.out.print("姓名 " );
System.out.print("英语 " );
System.out.print("高数 " );
System.out.println("JAVA " );
System.out.println();
//output = rs.getString(1);

while( rs.next() ) {
String tmp= rs.getString(1);
System.out.print( tmp );
output = output + tmp + " ";
//字段1
tmp= rs.getString(2);
System.out.print( tmp);
output = output + tmp+ " " ;
//output = output + rs.getString(2)+ " \n\t";
//字段2
tmp= rs.getString(3);
System.out.print( tmp );
output = output + tmp + " " ;
//output = output + rs.getString(3)+ " \n\t";
//字段3
tmp= rs.getString(4);
System.out.print(tmp );
output = output + tmp + " ";
//output = output + rs.getString(4)+ " \n\t";
//字段4
tmp= rs.getString(5);
System.out.println(tmp );
output = output + tmp +" \n\t";
//output = output + rs.getString(5)+ " \n\t";
//字段5
System.out.println();
}
System.out.println("=========");
System.out.println(output);
s = output;

}catch (Exception e) {
e.printStackTrace();
}

finally {
if (rs != null) try { rs.close(); } catch(Exception e) {}
if (stmt != null) try { stmt.close(); } catch(Exception e) {}
if (con != null) try { con.close(); } catch(Exception e) {}
}
}

}

运行后结果如下：
====SSSSSSSSSSSSSBBBB111====
null
====SSSSSSSSSSSSSEEEE111====
数据库联接成功!!
java.sql.SQLException: [Microsoft][ODBC SQL Server Driver][SQL Server]对象名 'tb2' 无效。
at sun.jdbc.odbc.JdbcOdbc.createSQLException(Unknown Source)
at sun.jdbc.odbc.JdbcOdbc.standardError(Unknown Source)
at sun.jdbc.odbc.JdbcOdbc.SQLExecDirect(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcStatement.execute(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcStatement.executeQuery(Unknown Source)
at BackgroundDemo.myPrint(BackgroundDemo.java:58)
at BackgroundDemo.start(BackgroundDemo.java:28)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
====SSSSSSSSSSSSSBBBB2222====
null
====SSSSSSSSSSSSSEEEE2222====
====XXXXXXXXXXXX====
Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException: String is null
at sun.java2d.SunGraphics2D.drawString(Unknown Source)
at BackgroundDemo.paint(BackgroundDemo.java:37)
at sun.awt.RepaintArea.paintComponent(Unknown Source)
at sun.awt.RepaintArea.paint(Unknown Source)
at sun.awt.windows.WComponentPeer.handleEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
====XXXXXXXXXXXX====
Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException: String is null
at sun.java2d.SunGraphics2D.drawString(Unknown Source)
at BackgroundDemo.paint(BackgroundDemo.java:37)
at sun.awt.RepaintArea.paintComponent(Unknown Source)
at sun.awt.RepaintArea.paint(Unknown Source)
at sun.awt.windows.WComponentPeer.handleEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

哪位大侠帮看一下，谢谢！！！

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