title: sql Exception Invalid string or Buffer Length
body: <p>i have started the java and just completed core java ...but i am not able to proceed further because of the sqlException..
  i have load the driver successfully and want to execute the query ...but every time i found Exception how can i get rid of this problem.....</p>
  
  <p>my code is as follows:</p>
  
  <pre><code>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);
      }   
  </code></pre>
  
  <p>this always shows : SQLException[Microsoft][ODBC Driver Manager] Invalid string or buffer length</p>
  
  <p>plz help me..fnds</p>