没有主键我无法查询表

Question

I'm trying to query through a model in Django that has no Primary Key . I need to query though it so I can access to the Foreign keys it has.

I'm just trying to do this atm and doesn't even work:

chars = Characterweapons.objects.all()

print(chars)

And if i change Characterweapons to Weapons for example, a table with Primary Key it works.

The error I get when I load the page is this:

Exception Value: (1054, "Unknown column 'characterweapons.id' in 'field list'")

This is my model:

class Characterweapons(models.Model):
    characterid = models.ForeignKey(Characters, models.DO_NOTHING, db_column='CharacterID')  # Field name made lowercase.
    weaponid = models.ForeignKey(Weapons, models.DO_NOTHING, db_column='WeaponID', blank=True, null=True)  # Field name made lowercase.
    categoryid = models.ForeignKey(Category, models.DO_NOTHING, db_column='CategoryID', blank=True, null=True)  # Field name made lowercase.
    quantity = models.IntegerField(db_column='Quantity', blank=True, null=True)  # Field name made lowercase.

    class Meta:
        managed = False
        db_table = 'characterweapons'

    def __str__(self):
        return '%s %s %s %s' % (self.quantity,self.characterid,self.weaponid,self.categoryid)

Anyone knows about this? Thanks in advance!

Answer 1

So it looks like you did a DBinspect on an existing database to generate this model. I'm guessing this is failing because Django ORM expects your table to have a primary key. "id" is the default name for a Django generated model primary key field. I suspect when you are trying to call Characterweapons.objects.all() it's trying to get the primary key field for some reason.

There may be a workaround but unless you really know what your doing with your database, I would highly urge you to set a primary key on your tables.

Answer 2

The best solution that I found, in this case, was to perform my own query, for example:

fact = MyModelWithoutPK.objects.raw("SELECT * FROM my_model_without_pk WHERE my_search=some_search")

This way you don't have to implement or add another middleware. see more at Django docs