I am following sentdex's tutorials for django web development, however I have hit a wall - the error shows:

> 
> django.db.utils.IntegrityError: The row in table 'main\_tutorial' with primary key '1' has an invalid foreign key: main\_tutorial.tutorial\_series\_id contains a value '1' that does not have a corresponding value in main\_tutorialseries.id.
> 
> 
> 

I've tried removing `default=1`, and `on_delete=models.SET_DEFAULT/CASCADE`.

I've also tried deleting the SQL database, migrations.
I've tried using SQ Browser for SQlite to try and change things.

Sadly I've spent hours staring at this and trying to find an answer, any help would be greatly appreciated. Thanks!
The code is :

```
from django.db import models
from datetime import datetime

class TutorialCategory(models.Model):

    tutorial_category = models.CharField(max_length=200)
    category_summary = models.CharField(max_length=200)
    category_slug = models.CharField(max_length=200, default=1)

    class Meta:
        # Gives the proper plural name for admin
        verbose_name_plural = "Categories"

    def __str__(self):
        return self.tutorial_category

class TutorialSeries(models.Model):
    tutorial_series = models.CharField(max_length=200, default=1)
    tutorial_category = models.ForeignKey(TutorialCategory, default=1,
                                          verbose_name="Category", on_delete=models.SET_DEFAULT)
    series_summary = models.CharField(max_length=200)

    class Meta:
        # otherwise we get "Tutorial Seriess in admin"
        verbose_name_plural = "Series"

    def __str__(self):
        return self.tutorial_series

class Tutorial(models.Model):
    tutorial_title = models.CharField(max_length=200)
    tutorial_content = models.TextField()
    tutorial_published = models.DateTimeField('date published')

    tutorial_series = models.ForeignKey(TutorialSeries, default=1, verbose_name="Series", on_delete=models.SET_DEFAULT)
    tutorial_slug = models.CharField(max_length=200)
    def __str__(self):
        return self.tutorial_title

```

Any details to help walk me through this obstacle would be greatly appreciated. Thanks!