Incrementing the slug by avoiding Integrity error in django models save method

django, integrity, model, save, slug

Solution

You will have to use loop instead of just a one condition. Try this:

class Publisher(models.Model):
    name = models.CharField(max_length=200)
    slug = models.SlugField(max_length=150, unique=True)    

    def save(self, *args, **kwargs):
        if not self.id and not self.slug:
            slug = slugify(self.name)
            slug_exists = True
            counter = 1
            self.slug = slug
            while slug_exists:
                try:
                    slug_exits = Publisher.objects.get(slug=slug)
                    if slug_exits:
                        slug = self.slug + '_' + str(counter)
                        counter += 1
                except Publisher.DoesNotExist:
                    self.slug = slug
                    break
        super(Publisher, self).save(*args, **kwargs)

Problem

I have a model with two fields as below models.py ``` class Publisher(models.Model): name = models.CharField(max_length=200) slug = models.SlugField(max_length=150, unique=True) def save(self, *args, **kwargs): if not self.id and not self.slug: slug = slugify(self.name) try: slug_exits = Publisher.objects.get(slug=slug) if slug_exits: self.slug = slug + '_1' except Publisher.DoesNotExist: self.slug = slug super(Publisher, self).save(*args, **kwargs) ``` Here i am creating a slug based on the `name` field as we can see above So when we try to create a publisher with `name already exists`, the `save` method of the model will add the `_1` to the end. And when we again try to create a new record with same `name`, an `Integrity` error will be raised as below ``` >> Publisher.objects.create(name="abc") result: slug will be "abc" >> Publisher.objects.create(name="abc") result: slug will be "abc_1" >> Publisher.objects.create(name="abc") result: ................. ................. 34 del cursor 35 del connection ---> 36 raise errorclass, errorvalue 37 38 re_numeric_part = re.compile(r"^(\d+)") IntegrityError: (1062, "Duplicate entry 'abc_1' for key 'slug'") ``` So what i am want is if the title/slug already exists in the database and if slug contains number in it(at the end like abc`_1`), we should increment it that number So what all i want is to `increment the number in the slug` as below if the title/slug already exists in the database ``` abc abc_1 abc_2 abc_3 ``` So can anyone please let me know how to implement the above logic of incrementing the slug ? Thanks in advance......

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