query in Sql with JDBC

In my table, I have ta开发者_高级运维ken capacity in this form. `capacity DECL(3,0) UNSIGNED

Is it correct??I am not sure if the above method is correct to do it in this way? if I have to do it with PreparedStatement, how would it work?

First of all your SQL query is incorrect.

SELECT max(f.capacity)-COALESCE(SUM(r.num_seats),0) AS seats_avail 
  FROM flights f,
       reservations r 
  WHERE f.flight_no="CSC585" 
    AND r.flight_no=f.flight_no
    AND r.departure_date="2010-05-31";

Java code will looks like

String sql = " SELECT max(f.capacity)-COALESCE(SUM(r.num_seats),0) AS seats_avail 
      FROM flights f,
           reservations r 
      WHERE f.flight_no=?
        AND r.flight_no=f.flight_no
        AND r.departure_date=?";

final PreparedStatement stmt = connectionHolder.prepareStatement(sql);

stmt.setString(1, "CSC585");
stmt.setString(2, "2010-05-31");

ResulSet rs = stmt.executeQuery();

while ( rs.next() ) {
  String seats = rs.getString("seats_avail");
  System.out.println(seats );
}