[BUG] New flight objects define their subclass object ids as null

[aasitvora99]

Describe the bug

Note

Not sure if this is by design, I raised as it seemed odd.

While creating new flight objects with POST /flights route, rocket_id and motor_id that get passed as strings get subbed with null while fetching the new object.

To Reproduce
Steps to reproduce the behavior:

1. Create a new flight object
   2.Run a GET /flight for the new flight object id received from 1
2. Check response body field, rocket_id and motor_id is defined null

Expected behavior
RFC. Is this by design?

Request Body

curl -X 'POST' \
 'http://localhost:8080/flights/' \
 -H 'accept: application/json' \
 -H 'Content-Type: application/json' \
 -d '{
 "name": "Flight",
 "environment": {
 "latitude": 0,
 "longitude": 0,
 "elevation": 1400,
 "atmospheric_model_type": "standard_atmosphere",
 "atmospheric_model_file": "GFS",
 "date": "2025-07-13T14:04:02.841000"
 },
 "rocket": {
 "motor": {
 "thrust_source": [
 [
 0.082,
 2651.855
 ],
 [
 0.249,
 2780.285
 ]
 ],
 "burn_time": 4.264,
 "nozzle_radius": 0.1,
 "dry_mass": 3.4048,
 "dry_inertia": [
 0,
 0,
 0
 ],
 "center_of_dry_mass_position": 0.1,
 "motor_kind": "GENERIC",
 "chamber_radius": 0.049,
 "chamber_height": 0.751,
 "chamber_position": 0,
 "propellant_initial_mass": 8.064,
 "nozzle_position": 0,
 "tanks": null,
 "grain_number": null,
 "grain_density": null,
 "grain_outer_radius": null,
 "grain_initial_inner_radius": null,
 "grain_initial_height": null,
 "grains_center_of_mass_position": null,
 "grain_separation": null,
 "throat_radius": null,
 "interpolation_method": "linear",
 "coordinate_system_orientation": "nozzle_to_combustion_chamber",
 "reshape_thrust_curve": false,
 "motor_id":"6872bc56d9d1ad60bef48dc2"
 },
 "radius": 0.1,
 "mass": 26,
 "motor_position": -0.06,
 "center_of_mass_without_motor": 0,
 "inertia": [
 0,
 0,
 0
 ],
 "power_off_drag": [
 [
 0,
 0
 ],
 [
 0.1,
 0.1
 ],
 [
 0.2,
 0.2
 ]
 ],
 "power_on_drag": [
 [
 0,
 0
 ],
 [
 0.1,
 0.1
 ],
 [
 0.2,
 0.2
 ]
 ],
 "coordinate_system_orientation": "tail_to_nose",
 "nose": {
 "name": "Nose",
 "length": 2,
 "kind": "vonKarman",
 "position": 1,
 "base_radius": 0.1,
 "rocket_radius": 0.1
 },
 "fins": [
 {
 "fins_kind": "trapezoidal",
 "name": "Fins",
 "n": 4,
 "root_chord": 0.25,
 "span": 0.15,
 "position": -0.5,
 "tip_chord": 0.15,
 "cant_angle": 0,
 "rocket_radius": 0.1,
 "airfoil": null
 }
 ],
 "parachutes": null,
 "rail_buttons": {
 "name": "RailButtons",
 "upper_button_position": 0.1,
 "lower_button_position": -0.1,
 "angular_position": 0
 },
 "tail": null,
 "rocket_id":"6872bc56d9d1ad60bef48dc9"
 },
 "rail_length": 6,
 "time_overshoot": true,
 "terminate_on_apogee": false,
 "equations_of_motion": "standard",
 "inclination": 85,
 "heading": 0,
 "max_time": null,
 "max_time_step": null,
 "min_time_step": null,
 "rtol": null,
 "atol": null,
 "verbose": null
 }'

[GabrielBarberini]

It's definitely a bug.

I guess it's a side effect of the way they get stored in DB.

Since the submodels don't have an ID their id field is None and somehow this is persisting them as null in the DB when in reality it should store nothing.

I'll take a look when I have some time and fix it.
Thanks for raising!