manytoone relationships to define a manytoone relationship use foreignkey if ticket 1578 ever slips back in these models will not be able to be created the field names being lowercased versions of their opposite classes is important here protect against repetition of 1839 2415 and 2536 multiple paths to the same model 7110 7125 test related objects visibility if ticket 1578 ever slips back in these models will not be able to be created the field names being lowercased versions of their opposite classes is important here protect against repetition of 1839 2415 and 2536 multiple paths to the same model 7110 7125 test related objects visibility
from django.db import models


class Reporter(models.Model):
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=30)
    email = models.EmailField()

    def __str__(self):
        return "%s %s" % (self.first_name, self.last_name)


class Article(models.Model):
    headline = models.CharField(max_length=100)
    pub_date = models.DateField()
    reporter = models.ForeignKey(Reporter, models.CASCADE)

    class Meta:
        ordering = ("headline",)

    def __str__(self):
        return self.headline


class Country(models.Model):
    id = models.SmallAutoField(primary_key=True)
    name = models.CharField(max_length=50)


class City(models.Model):
    id = models.BigAutoField(primary_key=True)
    country = models.ForeignKey(
        Country, models.CASCADE, related_name="cities", null=True
    )
    name = models.CharField(max_length=50)


class District(models.Model):
    city = models.ForeignKey(City, models.CASCADE, related_name="districts", null=True)
    name = models.CharField(max_length=50)

    def __str__(self):
        return self.name





class First(models.Model):
    second = models.IntegerField()


class Second(models.Model):
    first = models.ForeignKey(First, models.CASCADE, related_name="the_first")



class Third(models.Model):
    name = models.CharField(max_length=20)
    third = models.ForeignKey(
        "self", models.SET_NULL, null=True, related_name="child_set"
    )


class Parent(models.Model):
    name = models.CharField(max_length=20, unique=True)
    bestchild = models.ForeignKey(
        "Child", models.SET_NULL, null=True, related_name="favored_by"
    )


class ParentStringPrimaryKey(models.Model):
    name = models.CharField(primary_key=True, max_length=15)


class Child(models.Model):
    name = models.CharField(max_length=20)
    parent = models.ForeignKey(Parent, models.CASCADE)


class ChildNullableParent(models.Model):
    parent = models.ForeignKey(Parent, models.CASCADE, null=True)


class ChildStringPrimaryKeyParent(models.Model):
    parent = models.ForeignKey(ParentStringPrimaryKey, on_delete=models.CASCADE)


class ToFieldChild(models.Model):
    parent = models.ForeignKey(
        Parent, models.CASCADE, to_field="name", related_name="to_field_children"
    )



class Category(models.Model):
    name = models.CharField(max_length=20)

    def __str__(self):
        return self.name


class Record(models.Model):
    category = models.ForeignKey(Category, models.CASCADE)


class Relation(models.Model):
    left = models.ForeignKey(Record, models.CASCADE, related_name="left_set")
    right = models.ForeignKey(Record, models.CASCADE, related_name="right_set")

    def __str__(self):
        return "%s - %s" % (self.left.category.name, self.right.category.name)



class SchoolManager(models.Manager):
    def get_queryset(self):
        return super().get_queryset().filter(is_public=True)


class School(models.Model):
    is_public = models.BooleanField(default=False)
    objects = SchoolManager()


class Student(models.Model):
    school = models.ForeignKey(School, models.CASCADE)