Sql CONCAT function is not updating column

Question

Trying this syntax to populate a column from other columns.

SELECT CONCAT('Oferta,',`id`, ',', `nazwa`) as slug FROM `maszyny`;

Here 'Oferta' is hard coded string. Its showing a result with above concat format but column 'slug' didnt populate with data. What i am missing?

You can learn more about slug here
https://stackoverflow.com/questions/427102/what-is-a-slug-in-django?rq=1 — John Albert Flores, May 10 '20 at 11:58

score 1 · Answer 1 · answered May 10 '20 at 12:36

I've added some comments to your code, please let me know if something's still unclear so I can update it with more information:

    class ArticlePkAndSlug(models.Model):
        title = models.CharField(max_length=settings.BLOG_TITLE_MAX_LENGTH)

        # editable=False means that slug will be created only once and then it won't be updated
        slug = models.SlugField(default="", editable=False, max_length=settings.BLOG_TITLE_MAX_LENGTH)  

        def get_absolute_url(self):
            # this method returns an absolute URL to object details, which consists of object ID and its slug
            kwargs = {"pk": self.id, "slug": self.slug}
            return reverse("article-pk-slug-detail", kwargs=kwargs)  

        def save(self, *args, **kwargs):
            value = self.title
            self.slug = slugify(value, allow_unicode=True)  
            # here the title of an article is slugifyed, so it can be easily used as a URL param
            super().save(*args, **kwargs)

Sql CONCAT function is not updating column

1 Answers1