Exporting a field from another model, using foreign key - django

Question

I've just set up the whole import-export thing and I just can't make it export a field from another model, using the foreign key.
models.py
from django.db import models
from django.contrib.auth.models import User
from datetime import date
from .validators import validate_file_size
# Create your models here.
class CORMeserii(models.Model):
CodCOR = models.CharField(max_length=25, primary_key=True, unique=True)
MeserieCor = models.CharField(max_length=50, unique=True)
def __str__(self):
return str(self.CodCOR + " - " + self.MeserieCor)
class Meta:
verbose_name_plural = "CORuri"
class Oferta(models.Model):
solicitant = models.ForeignKey(User, on_delete=models.CASCADE)
cor = models.ForeignKey(CORMeserii, on_delete=models.CASCADE)
dataSolicitare = models.DateField(default=date.today)
locuri = models.IntegerField()
agentEconomic = models.CharField(max_length=50)
adresa = models.CharField(max_length=150)
dataExpirare = models.DateField()
experientaSolicitata = models.CharField(max_length=200)
studiiSolicitate = models.CharField(max_length=200)
judet = models.CharField(max_length=20)
localitate = models.CharField(max_length=25)
telefon = models.CharField(max_length=12)
emailContact = models.EmailField(max_length=40)
rezolvata = models.BooleanField(default=False)
def __str__(self):
return str(self.cor)
admin.py
from django.contrib import admin
from .models import Oferta, CORMeserii
from import_export import resources
from import_export.admin import ImportExportMixin, ImportExportModelAdmin
import tablib
# Register your models here.
class CorImEx(resources.ModelResource):
class Meta:
model = CORMeserii
class CorAdmin(ImportExportMixin, admin.ModelAdmin):
list_display = ('CodCOR', 'MeserieCor')
resource_class = CorImEx
class CorImExAdmin(ImportExportModelAdmin):
resource_class = CorImEx
class OferteImEx(resources.ModelResource):
class Meta:
model = Oferta
fields = ('id', 'solicitant', 'cor', 'oferta.cor.MeserieCor')
class OfertaAdmin(ImportExportMixin, admin.ModelAdmin):
list_display = ('id', 'solicitant', 'dataExpirare', 'dataSolicitare')
resource_class = OferteImEx
class OferteImExAdmin(ImportExportModelAdmin):
resource_class = OferteImEx
admin.site.register(Oferta, OfertaAdmin)
admin.site.register(CORMeserii, CorAdmin)
You can see it in the OferteImEx class - the field 'oferta.cor.MeserieCor'.
I want to export the MeserieCor field from the model CORMeserii - but I can't figure it out.
I tried with: 'oferta.cor.MeserieCor',
cor.MeserieCor', 'MeserieCor' (even though the last 2 ones don't make sense to me at all).
Is there any way to export that field somehow, even though it is from another model? (I'm pretty sure there is but I can't figure it out)
Thanks.

Answer 1

In Django you use double underscore (__) to follow relationship in lookups. It's in the documentation:
Django offers a powerful and intuitive way to “follow” relationships in lookups, taking care of the SQL JOINs for you automatically, behind the scenes. To span a relationship, just use the field name of related fields across models, separated by double underscores, until you get to the field you want.
Link: Lookups that span relationship
There is even an example in the django import export documentation how to follow relationship:
When defining ModelResource fields it is possible to follow model relationships:
class BookResource(resources.ModelResource):
class Meta:
model = Book
fields = ('author__name',)
Source: https://django-import-export.readthedocs.io/en/latest/getting_started.html#customize-resource-options