String query="select * from s where SID='01'";
try{
     Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
    Connection conn = DriverManager.getConnection 
       ("jdbc:odbc:login","sa","sa"); 
     Statement stmt=conn.createStatement();
     ResultSet rs=stmt.executeQuery(query);
     boolean more=rs.next();
     if(more){
     System.out.print("有记录");
     }
                   else
                           System.out.print("无记录");    
     rs.close();
conn.close();
                          ..............