CODEWITHSUNDEEP
djangodjango-views
metraon
metraon

Reputation: 1259

Django view foreign key in a backward relationship

I have those models :

Each student have a personal teacher :

class Student(models.Model):
    name= models.CharField(max_length=200, default='', blank=True)
    group= models.CharField(max_length=200, default='', blank=True)
    teacher= models.ForeignKey(Teacher, null=True, blank=True)
    session = models.IntegerField(default=99, blank=True)
    def __str__(self):
        return self.name

A teacher can teach at one, two, three, fours sessions. 

class Teacher(Employe):
    ...
    session1 = models.NullBooleanField(default='', blank=True)
    session2 = models.NullBooleanField(default='', blank=True)
    session3 = models.NullBooleanField(default='', blank=True)
    session4 = models.NullBooleanField(default='', blank=True)

    def __str__(self):
        return self.name

Each classroom only have one teacher for that particular session.

class Classroom(models.Model):
    code = models.CharField(max_length=10, default='', blank=True)
    teacherSession1 = models.ForeignKey(Teacher, null=True, blank=True, related_name='S1')
    teacherSession2 = models.ForeignKey(Teacher, null=True, blank=True, related_name='S2')
    teacherSession3 = models.ForeignKey(Teacher, null=True, blank=True, related_name='S3')
    teacherSession4 = models.ForeignKey(Teacher, null=True, blank=True, related_name='S4')

    def __str__(self):
        return self.code

I want to build a query that would output something like that :

Student name, Student group, Classroom (for session 1 to 4)

So far I have came up with this, but I struggle at getting the classroom code.

def list_student_plan(session):
    my_list = Student.objects.values('name', 'group', 'teacher__name').filter(Q(session=session))
    return my_list

Upvotes: 0

Views: 471

Answers (1)

Jody Fitzpatrick
Jody Fitzpatrick

Reputation: 357

This is my recommend models

Groups

class Groups(models.Model):

    name    = models.CharField(max_length=200)
    description   = models.CharField(max_length=255, blank=True)


    def __str__(self):
        return self.name

Student Model

class Student(models.Model):

    name    = models.CharField(max_length=200, default='', blank=True)
    group   = models.ForeignKey(Groups, null=True, blank=True, unique=False)

    def __str__(self):
        return self.name

Code Model

class Code(models.Model):
     name = models.CharField(max_length=200)
     code = models.CharField(max_length=25)
     description = models.CharField(max_length=255)

def __str__(self):
    return self.name

Teacher Model

class Teacher(models.Model):
     name = models.CharField(max_length=200)
     code = models.ForeignKey(Code, unique=False)

def __str__(self):
    return self.name + " " + self.code.name

Sessions

class Sessions(Employe):
     teacher = models.ForeignKey(Teacher, unique=False)
     student = models.ForeignKey(Student, unique=False)
     session = models.IntegerField(null=True, blank=True)

def __str__(self):
    return self.teacher.name + ' ' + self.student.name

Now with "Sessions" will help you better manage, where session would contain a value between 1-4 ( and possible more - imagine if you added an extra period to the day ). With teacher you will get a code, you can have multiple teachers with multiple codes, or the same teacher with multiple codes. I hope this gets you in the right direction and this in my opinion is a much cleaner way to approach this problem, let me know if you have any issues and I will add more details.

Upvotes: 1

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