如何在Django中引用一组模型字段？

Question

Let's say I had the following Django model:

class Person(models.Model):
    name = models.CharField()
    age = models.IntegerField()
    country = models.ForeignKey(Country)
    company = models.ForeignKey(Company)

My app can search for people based on some criteria and then return a table with the results, showing only specific columns that the user requested.

Now I want to store searches in the database, along with the columns that are displayed.

class SavedSearch(models.Model):
    title = models.CharField()
    q_object = models.BinaryField()
    display_fields = ???

What is the best way to store which fields from the Person model will be displayed?

Currently I'm just storing a JSON list of the field names (eg ['name','age'] ) in a TextField but I'm wondering if there's a better way to store references to model fields.

I'd also like to be able to store fields from related (through ForeignKey) models. So something like ['name','age','company__website'] .

Answer 1

I am afraid you can not save the reference to model fields that way, but you can use a computed property that will save the model name and return field references as required -

• Save the model name along with the fields.

   class SavedSearch(models.Model): title = models.CharField() q_object = models.BinaryField() model_name = models.CharField() # 'app_label.Person' display_fields = models.CharField() # 'name,age,company__website' -> comma separated vaulues 

• Then add the computed property -

    @property def display_fields_property(self): from django.apps import apps properties = [] # get the model class using apps from django.apps model = apps.get_model(app_label=self.model_name.split('.')[0], model_name=self.model_name.split('.')[1]) for x in self.display_fields.split(','): # get the property from the model class properties.append(getattr(model, x) # properties contains field reference of the model fields return properties