django-import-export ForeignKey widget returns empty values (Django 1.10)

Question

I'm trying to export Student, which has a OneToOne relationship with Django built-in User model. But when I export Students, the username column is empty in the exported file.

# models.py    
class Student(models.Model):
        user = models.OneToOneField(User, verbose_name=_('user'))
        student_number = models.CharField(unique=True, null=False, max_length=10, verbose_name=_('student number'))
        score = models.PositiveIntegerField(default=0, verbose_name=_('score'))

        def __str__(self):
            return self.user.get_full_name()

# admin.py
class StudentResource(resources.ModelResource):
    username = fields.Field(column_name='username', attribute='User',
               widget=widgets.ForeignKeyWidget(model=User, field='username'))

    class Meta:
        model = Student
        fields = ('id', 'username', 'student_number', 'score',)

class StudentAdmin(ImportExportActionModelAdmin):
    resource_class = StudentResource

admin.site.register(Student, StudentAdmin)

I get result when replace StudentResource class with this:

class StudentResource(resources.ModelResource):

    class Meta:
        model = Student
        fields = ('id', 'user__username', 'student_number', 'score',)

but then I would have problem when importing data. Any idea?

Reza · Accepted Answer · 2017-02-24 09:19:47Z

3

Well, it is about the capitalized 'User' in attribute='User' in username field. I thought it might be good to explain more about using ForeignKeyWidget.

To use ForeignKeyWidget you should specify these elements:

Specify a column_name which is the name of the column in your import/export file.
In attribute, determine the name of the field of your current model, which is a OneToOneField or a ForeignKey. In my case it is user in Student model.
In ForeignKeyWidget specify the name of related model and one of its fields which you want to get data from. In my case the related model is User and the field is its username field.

answered Feb 24, 2017 at 9:19

Reza

1,1242 gold badges10 silver badges19 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

cbasah Over a year ago

Thank you very much for this answer. Your explanation is better than the official django-import-export documentation.

Collectives™ on Stack Overflow

django-import-export ForeignKey widget returns empty values (Django 1.10)

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related