+$sql_pquery = "select CapAv, sum(NbPlaces) as BookedPlaces
+ from RESERVATIONS, VOLS, AVIONS
+ where RESERVATIONS.NumVol = VOLS.NumVol and AVIONS.NumAv = VOLS.NumAv and
+ RESERVATIONS.NumVol = ?
+ group by RESERVATIONS.NumVol";
+$connection->prepare_query($sql_pquery);
+$connection->prepared_query_bind_param("s", array($flight_id));
+$connection->run_prepared_query();
+$connection->get_pquery_result();
+$rows_cap = $connection->get_result_array();
+$connection->close_prepared_query();
+//var_dump($rows_cap);
+$booked_places = $rows_cap[0]['BookedPlaces'];
+if (is_null($booked_places)) {
+ $booked_places = 0;
+}
+if (isset($rows_cap[0]['CapAv']) && isset($booked_places)) {
+ $free_places = $rows_cap[0]['CapAv'] - $booked_places;
+} else {
+ $free_places = "Inconnu";
+}