Question

I need to build a generic django object having dynamic parameters. that is parameters that can be different from one object to another. I cannot create different models because parameters can change at any time and I do not want to use a PickledField because SQL database should be accessed outside python.

I made these models :

class DynamicObject(models.Model):
    uuid = UUIDField(primary_key=True, editable=False)
    synopsis = models.CharField(max_length=64)
    created = models.DateTimeField(auto_now_add=True)
    modified = models.DateTimeField(auto_now=True)

class DynamicObjectParam(models.Model):
    obj = models.ForeignKey(DynamicObject,related_name='params')
    name = models.CharField(max_length=30)
    value = models.CharField(max_length=255)


To list parameters for a particular object, I do :
obj = DynamicObject.objects.get(uuid='xxx')
for p in obj.params:
    print p.name,p.value

It is quite easy,
but how can I do to select objects having a specific parameter, for exemple :
what are DynamicObjects having a parameter named ‘server_name’ and a value ‘Sun SF25K’ ?

Answer 1

Give this a try:

results = DynamicObject.objects.filter(params__name__exact='server_name',params__value__exact='Sun SF25K')