After creating a new class Airport and make some changes in flights when i migrate it after makemigrations throws IntegrityError

Question

from django.db import models

Create your models here.

class Airport(models.Model):
    code = models.CharField(max_length=3)
    city = models.CharField(max_length=64)

    def __str__(self):
        return f"{self.city}, ({self.code})"
class Flight(models.Model):
    origin = models.ForeignKey(Airport, on_delete= models.CASCADE, related_name="departures" )
    destination = models.ForeignKey(Airport, on_delete=models.CASCADE, related_name="arrivals")
    duration = models.IntegerField()

    def __str__(self):
        return (f"{self.origin} To {self.destination}")

ERROR

On running command python manage.py migrate, it shows IntegrityError.

Operations to perform: Apply all migrations: admin, auth, contenttypes, flights, sessions Running migrations: Applying flights.0002_auto_20201119_1418...Traceback (most recent call last): File "C:\Users\arora\Documents\Harvard\lec-4\airline\manage.py", line 22, in main() File "C:\Users\arora\Documents\Harvard\lec-4\airline\manage.py", line 18, in main execute_from_command_line(sys.argv) File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\core\management_init_.py", line 401, in execute_from_command_line utility.execute() File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\core\management_init_.py", line 395, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\core\management\base.py", line 330, in run_from_argv self.execute(*args, **cmd_options) File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\core\management\base.py", line 371, in execute output = self.handle(*args, **options) File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\core\management\base.py", line 85, in wrapped res = handle_func(*args, **kwargs) File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\core\management\commands\migrate.py", line 243, in handle post_migrate_state = executor.migrate( File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\db\migrations\executor.py", line 117, in migrate state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial) File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\db\migrations\executor.py", line 147, in _migrate_all_forwards state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial) File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\db\migrations\executor.py", line 229, in apply_migration migration_recorded = True File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\db\backends\sqlite3\schema.py", line 35, in exit self.connection.check_constraints() File "C:\Users\arora\Documents\Harvard\lec-4\venv\lib\site-packages\django\db\backends\sqlite3\base.py", line 343, in check_constraints raise IntegrityError( django.db.utils.IntegrityError: The row in table 'flights_flight' with primary key '1' has an invalid foreign key: flights_flight.origin_id contains a value 'new york' that does not have a corresponding value in flights_airport.id.

andream andream · Accepted Answer · 2020-12-30T11:40:24

you need to delete the flight entry you made previously. use flight.delete() in the shell

(you will need to also reset the code to the previous values of origin and destination as CharFields and not ForeignKeys, makemigration again to remove the airport class, migrate changes and go back in the shell, access the flight in the database and delete it ..the go back and make the changes with the airport class)

After creating a new class Airport and make some changes in flights when i migrate it after makemigrations throws IntegrityError

Create your models here.

1 Answers