from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation

from django.contrib.contenttypes.models import ContentType

from django.db import models

class Square(models.Model):

    root = models.IntegerField()

    square = models.PositiveIntegerField()

    def __str__(self):

        return "%s ** 2 == %s" % (self.root, self.square)

class Person(models.Model):

    first_name = models.CharField(max_length=20)

    last_name = models.CharField(max_length=20)

    def __str__(self):

        return "%s %s" % (self.first_name, self.last_name)

class SchoolClassManager(models.Manager):

    def get_queryset(self):

        return super().get_queryset().exclude(year=1000)

class SchoolClass(models.Model):

    year = models.PositiveIntegerField()

    day = models.CharField(max_length=9, blank=True)

    last_updated = models.DateTimeField()

    objects = SchoolClassManager()

class VeryLongModelNameZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ(models.Model):

    primary_key_is_quite_long_zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz = models.AutoField(

        primary_key=True

    )

    charfield_is_quite_long_zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz = models.CharField(

        max_length=100

    )

    m2m_also_quite_long_zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz = (

        models.ManyToManyField(Person, blank=True)

    )

class Tag(models.Model):

    name = models.CharField(max_length=30)

    content_type = models.ForeignKey(

        ContentType, models.CASCADE, related_name="backend_tags"

    )

    object_id = models.PositiveIntegerField()

    content_object = GenericForeignKey("content_type", "object_id")

class Post(models.Model):

    name = models.CharField(max_length=30)

    text = models.TextField()

    tags = GenericRelation("Tag")

    class Meta:

        db_table = "CaseSensitive_Post"

class Reporter(models.Model):

    first_name = models.CharField(max_length=30)

    last_name = models.CharField(max_length=30)

    def __str__(self):

        return "%s %s" % (self.first_name, self.last_name)

class ReporterProxy(Reporter):

    class Meta:

        proxy = True

class Article(models.Model):

    headline = models.CharField(max_length=100)

    pub_date = models.DateField()

    reporter = models.ForeignKey(Reporter, models.CASCADE)

    reporter_proxy = models.ForeignKey(

        ReporterProxy,

        models.SET_NULL,

        null=True,

        related_name="reporter_proxy",

    )

    def __str__(self):

        return self.headline

class Item(models.Model):

    name = models.CharField(max_length=30)

    date = models.DateField()

    time = models.TimeField()

    last_modified = models.DateTimeField()

    def __str__(self):

        return self.name

class Object(models.Model):

    related_objects = models.ManyToManyField(

        "self", db_constraint=False, symmetrical=False

    )

    obj_ref = models.ForeignKey("ObjectReference", models.CASCADE, null=True)

    def __str__(self):

        return str(self.id)

class ObjectReference(models.Model):

    obj = models.ForeignKey(Object, models.CASCADE, db_constraint=False)

    def __str__(self):

        return str(self.obj_id)

class ObjectSelfReference(models.Model):

    key = models.CharField(max_length=3, unique=True)

    obj = models.ForeignKey("ObjectSelfReference", models.SET_NULL, null=True)

class CircularA(models.Model):

    key = models.CharField(max_length=3, unique=True)

    obj = models.ForeignKey("CircularB", models.SET_NULL, null=True)

    def natural_key(self):

        return (self.key,)

class CircularB(models.Model):

    key = models.CharField(max_length=3, unique=True)

    obj = models.ForeignKey("CircularA", models.SET_NULL, null=True)

    def natural_key(self):

        return (self.key,)

class RawData(models.Model):

    raw_data = models.BinaryField()

class Author(models.Model):

    name = models.CharField(max_length=255, unique=True)

class Book(models.Model):

    author = models.ForeignKey(Author, models.CASCADE, to_field="name")

class SQLKeywordsModel(models.Model):

    id = models.AutoField(primary_key=True, db_column="select")

    reporter = models.ForeignKey(Reporter, models.CASCADE, db_column="where")

    class Meta:

        db_table = "order"