How to get specific key for manytomany and foreignkey - django

Question

I have three models:
class Section(models.Model):
name = models.CharField()
class ParamText(models.Model):
text = models.TextField()
class Param(models.Model):
name = models.CharField()
value = models.IntegerField()
texts = models.ManyToManyField(ParamText)
section = models.ForeignField(Section)
This is simple example. Now I want to create class with concrete datas:
class ObjectTemplate(models.Model):
params = models.ManyToManyField(Param)
but I want put this model concrete ParamText in specyfic Param. My ObjectTemplate should contain many params[Param] (unique would be great) with only one selected ParamText for each Param.
How to realize this?

Answer 1

first of all to create a unique parmas[parm] use the OneToOneField instead of manytomany .
and to access a specific key : every object has an id so you can use that
let p be an Param's object
so to get the section id from the param you have to use
p.section.id
this would return a long int containing the id (primarykey) of the object.
I think the following will solve your one parmatext for each parma problem
class Section(models.Model):
name = models.CharField()
class ParamText(models.Model):
text = models.TextField()
class Param(models.Model):
name = models.CharField()
value = models.IntegerField()
texts = models.OneToOneField(ParamText)
section = models.ForeignField(Section)