django.db.utils.IntegrityError: UNIQUE constraint failed: new__vacancies_company.owner_id error

Question

I try to migrate and an error occurs:

django.db.utils.IntegrityError: UNIQUE constraint failed: new__vacancies_company.owner_id

from django.db import models
from django.contrib.auth.models import User


class Company(models.Model):
    name = models.CharField(max_length=64)
    location = models.CharField(max_length=64)
    logo = models.ImageField(upload_to="MEDIA_COMPANY_IMAGE_DIR")
    description = models.TextField()
    employee_count = models.IntegerField()
    owner = models.OneToOneField(User, on_delete=models.CASCADE, related_name="owner_user")


class Specialty(models.Model):
    code = models.CharField(max_length=32)
    title = models.CharField(max_length=32)
    picture = models.ImageField(upload_to="MEDIA_SPECIALITY_IMAGE_DIR")


class Vacancy(models.Model):
    title = models.CharField(max_length=100)
    specialty = models.ForeignKey(Specialty, on_delete=models.CASCADE, related_name="vacancies")
    company = models.ForeignKey(Company, on_delete=models.CASCADE, related_name="vacancies")
    skills = models.TextField()
    description = models.TextField()
    salary_min = models.FloatField()
    salary_max = models.FloatField()
    published_at = models.DateTimeField()


class Application(models.Model):
    written_username = models.CharField(max_length=24)
    written_phone = models.CharField(max_length=12)
    written_cover_letter = models.CharField(max_length=300)
    vacancy = models.ForeignKey(Vacancy, on_delete=models.CASCADE, related_name="applications")
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name="applications")

python manage.py runserver result:

OperationalError at / no such column: vacancies_company.owner_id

Answer 1

this happen to me when i try to add new models with foreign keys and the old models already have some data in them. if that is the case:

what i do is :

• comment the new models
• runserver
• delete every data in my models in the admin page
• uncomment the new models
• makemigration and migrate

if it persists

• redo steps and re-create superuser

if still

• delete the database file (sqlite file from directory)
• in you app delete migrations except (init.py) file
• makemigration and migrate

that is usually how i treat it , hope thay'll help