SQL異常無效的字符串或緩衝區長度

Question

我已經啓動了Java並剛剛完成了核心Java ...但我無法繼續進行，因爲sqlException .. 我已成功加載驅動程序並希望執行查詢...但我每次發現異常時我怎樣才能擺脫這個問題的.....

我的代碼如下：

if(e.getSource()==b1) 
    { 
     if(t1.getText().equals("")) 
     { 
      JOptionPane.showMessageDialog(null,"provide username to login"); 
      t1.requestFocus(); 
     } 
     else if(t2.getText().equals("")) 
     { 
      JOptionPane.showMessageDialog(null,"provide password to login"); 
      t2.requestFocus(); 
     } 
     else 
     { 
      String tablename=null; 
      if(rb==1) 
      {tablename="Admin";} 
      else if(rb==2) 
      {tablename="Clerks";} 
      else if(rb==3) 
      {tablename="members";} 
       try 
       { 
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); 
        Connection con=DriverManager.getConnection("Jdbc:Odbc:librarysystem","",""); 
        PreparedStatement ps=con.prepareStatement("select * from "+tablename+" where username=? and password=?"); 
        ps.setString(1,t1.getText()); 
        ps.setString(2,t2.getText()); 
        ResultSet rs=ps.executeQuery(); 
        if(rs.next()) 
        { 
         //System.out.println(res); 
         //JOptionPane.showMessageDialog(new JFrame(),"Registered user successful"); 
         l=new library(); 
        } 
        else 
        { 
         JOptionPane.showMessageDialog(new JFrame(),"wrong details entered"); 
        } 
       } 
       catch(Exception sql) 
       { 

        t1.setText (""); 
        t2.setText (""); 
        t1.requestFocus(); 
        System.out.println(sql); 
        JOptionPane.showMessageDialog (null, "Incorrect excep Information Provided."); 
       } 
     } 
    } 
    else if(e.getSource()==jrb1) 
    { 
     rb=1; 
    } 
    else if(e.getSource()==jrb2) 
    { 
     rb=2; 
    } 
    else if(e.getSource()==jrb3) 
    { 
     rb=3; 
    } 
    else if(e.getSource()==b2) 
    { 
     f.setVisible(false); 
     f.dispose(); 
     System.exit(152); 
    } 

這總是顯示：的SQLException [微軟] [ODBC驅動程序Manager]無效的字符串或緩衝區長度

個plz幫助me..fnds

Answer 1

它可以通過一個零長度字符串引起作爲您的SQL登錄：

連接CON =的DriverManager.getConnection（爲 「jdbc：ODBC：librarysystem」， 「山」，「sa_password 「）;