Question

I imported my (PHP) old site’s database tables into Django. By default it created a bunch of primary key fields within the model (since most of them were called things like news_id instead of id).

I just renamed all the primary keys to id and removed the fields from the model. The problem then came specifically with my News model. New stuff that I add doesn’t appear in the admin. When I remove the following line from my ModelAdmin, they show up:

list_display = ['headline_text', 'news_category', 'date_posted', 'is_sticky']

Specifically, it’s the news_category field that causes problems. If I remove it from that list then I see my new objects. Now, when I edit those items directly (hacking the URL with the item ID) they have a valid category, likewise in the database. Here’s the model definitions:

class NewsCategory(models.Model):

    def __unicode__(self):
        return self.cat_name

    #news_category_id = models.IntegerField(primary_key=True, editable=False)
    cat_name = models.CharField('Category name', max_length=75)
    cat_link = models.SlugField('Category name URL slug', max_length=75, blank=True, help_text='Used in URLs, eg spb.com/news/this-is-the-url-slug/ - generated automatically by default')

    class Meta:
        db_table = u'news_categories'
        ordering = ["cat_name"]
        verbose_name_plural = "News categories"

class News(models.Model):

    def __unicode__(self):
        return self.headline_text

    #news_id = models.IntegerField(primary_key=True, editable=False)
    news_category = models.ForeignKey('NewsCategory')
    writer = models.ForeignKey(Writer) # todo - automate
    headline_text = models.CharField(max_length=75)
    headline_link = models.SlugField('Headline URL slug', max_length=75, blank=True, help_text='Used in URLs, eg spb.com/news/this-is-the-url-slug/ - generated automatically by default')
    body = models.TextField()
    extra = models.TextField(blank=True)
    date_posted = models.DateTimeField(auto_now_add=True)
    is_sticky = models.BooleanField('Is this story featured on the homepage?', blank=True)
    tags = TaggableManager(blank=True)

    class Meta:
        db_table = u'news'
        verbose_name_plural = "News"

You can see where I’ve commented out the autogenerated primary key fields.

It seems like somehow Django thinks my new items don’t have news_category_ids, but they definitely do. I tried editing an existing piece of news and changing the category and it worked as normal. If I run a search for one of the new items, it doesn’t show up, but the bottom of the search says “1 News found”, so something is going on.

Any tips gratefully received.

EDIT: here’s my ModelAdmin too:

class NewsCategoryAdmin(admin.ModelAdmin):
    prepopulated_fields = {"cat_link": ("cat_name",)}
    list_display = ['cat_name', '_cat_count']

    def _cat_count(self, obj):
        return obj.news_set.count()
    _cat_count.short_description = "Number of news stories"      

class NewsImageInline(admin.TabularInline):
    model = NewsImage
    extra = 1    

class NewsAdmin(admin.ModelAdmin):
    prepopulated_fields = {"headline_link": ("headline_text",)}
    list_display = ['headline_text', 'news_category', 'date_posted', 'is_sticky'] #breaking line
    list_filter = ['news_category', 'date_posted', 'is_sticky']
    search_fields = ['headline_text']
    inlines = [NewsImageInline]

Answer 1

The answer you are looking for I think would lie in the SQL schema that you altered and not in the django models.

It could probably have something to do with null or blank values in the news_category_id, or news that belongs to a category that doesn’t exist in the news_category. Things I’d check:

• You have renamed the primary key on the News category from news_category_id to id. Does the foreign key on the News also map to news_category_id and not anything else?
• Are all the values captured in the news.news_category also present in news_category.id

Also, as an aside, I don’t see any reason why you need to rename the primary keys to id from something that they already are. Just marking them primary_key=True works just fine. Django provides you a convenient alias pk to access a model’s integer primary key, irrespective of what the name of the field actually is.