Django-tables2: How to use accessor to bring in foreign columns?

Question

I've tried reading the docs and previous answers to this question without much luck.

I've got a bunch of student-course registrations and I'd like to see some of those selected registrations in conjunction with some of the attributes of the students. No luck so far...I'd request your advice!

Here's the model:

class Student(models.Model):
    first_name = models.CharField(max_length=50)
    last_name = models.CharField(max_length=50)
    netID = models.CharField(max_length=8)

class Registration(models.Model):
    student = models.ForeignKey(Student)
    course = models.ForeignKey(Course)
    attendance_M = models.BooleanField(default=False)
    attendance_Tu = models.BooleanField(default=False)

and here is the tables.py:

class AttendanceTable(tables.Table):
    netID = tables.Column(accessor='Student.netID')
    first = tables.Column(accessor='Student.first_name')
    last = tables.Column(accessor='Student.last_name')
    class Meta:
        model = Registration
        attrs = {"class": "paleblue"}
        fields = ('attendance_M', 'attendance_Tu',)
        sequence = ('netID', 'first', 'last', 'attendance_M', 'attendance_Tu',)

While I'm getting data on the attendance values, there's nothing from the student foreign columns.

netID   First   Last    Attendance M    Attendance Tu
 —         —      —      ✔               ✘ 

And it's the same deal if I start the Table with model = Student and use accessors against the Registration table, it's the same deal.

I feel like I'm missing something very conceptual and crucial -- please guide me!

Chatelain

shouldn't it be accessor='student.netID', student.first_name, student.last_name (lowercase student) – Ultrastructure

Aha! That's right. Thank you. – Chatelain

Answer 1

The model name in the accessor parameter of the column should be lowercase.

Use accessor='student.netID' instead of accessor='Student.netID'.

Treachery

Answer 2

When using the accessor parameter, you have to use the field name stated in the Model that has the foreign key, and then select which field from that table you want to use.

So, for these models:

#models.py
class Description_M(models.Model):
   id_hash = models.CharField(db_column='Id_hash', primary_key=True, max_length=22)
   description = models.CharField(db_column='Description', max_length=255, blank=True, null=True)

class GeoCodes(models.Model):
    geo = models.CharField(db_column='Geo', primary_key=True, max_length=5)
    city_name = models.CharField(db_column='City', max_length=150, blank=True, null=True)

class RefSources(models.Model):
    id_source   = models.IntegerField(db_column='Id_source', primary_key=True,)  
    source_name   = models.CharField(db_column='Source', max_length=150, blank=True, null=True)  

class Price(models.Model):
    id_hash = models.ForeignKey(Description_M, models.DO_NOTHING, db_column='Id_hash')
    date= models.ForeignKey(DateTime, models.DO_NOTHING, db_column='Date')
    geo = models.ForeignKey(GeoCodes, models.DO_NOTHING, db_column='Geo')
    id_source = models.ForeignKey(RefSources, models.DO_NOTHING, db_column='Id_source')  # Field name made lowercase.
    price = models.FloatField(db_column='Price',primary_key=True, unique=False,default=None)

When using the foreign key to pull fields from that table, you have to:

class price_table(tables.Table):
    description = tables.Column(accessor = 'id_hash.description')
    city = tables.Column(accessor = 'geo.city_name')
    source = tables.Column(accessor = 'id_source.source_name')
    class Meta:
        model = Price
        fields = ['date','price']
        sequence = ['description ','date','city ','source','price']
        template_name = 'django_tables2/bootstrap.html'

Jipijapa