My problem is that I don't really know how to put my design in terms of a relational db.
I have a class 'Feat', which should contain several other classes, namely lists of 'Stat's, 'Skill's and 'Attribute's. The exact number of those depends on the instance of 'Feat', so I can't just define a static number of fields.
In normal Python, I'd simply use lists:
class Feat():
name
desc
att_effects = []
skill_effects = []
stat_effects = []
I tried to replicate this in Django using the Many-to-Many relationship, but that didn't quite work out.
class Attribute_Name(models.Model):
name = models.CharField(max_length=100)
desc = models.TextField()
def __unicode__(self):
return str(self.name)
...
class Attribute(models.Model):
name = models.ForeignKey(Attribute_Name)
value = models.IntegerField()
def __unicode__(self):
return "%s: %s" % (self.name, self.value)
...
class Feat(models.Model):
name = models.CharField(max_length=100)
desc = models.TextField()
att_effects = models.ManyToManyField(Attribute)
skill_effects = models.ManyToManyField(Skill)
stat_effects = models.ManyToManyField(Stat)
With these models, I could create new 'Attribute's when creating a new 'Feat' in the admin interface. However, I would always see all existing 'Attribute's, not just those pertaining to my new 'Feat'. Is there a way to restrict the view to only those created along with the new 'Feat'? Something like a back-link to the 'Feat' which created the 'Attribute'?
Basically, when I create or edit a 'Feat', I should only be able to use 'Attribute's created from the page of this instance or add a new 'Attribute' instance. I don't want 'Attribute's belonging to another 'Feat' (or another unrelated class) to show up.
Note that I don't want to add a field to the 'Attribute' class, since it should also be used along with other classes (eg 'Character')
I'd also like to do this within the admin interface, since it saves me quite a bit of work.
On a related note: Is there a way to leave a Many-to-Many field empty? Or should I just create a magic 'empty' value and set it as the default?
