from django.db import models class Product(models.Model): price = models.IntegerField(null=True) discounted_price = models.IntegerField(null=True) unit = models.CharField(max_length=15, null=True) class Meta: required_db_features = { "supports_table_check_constraints", } constraints = [ models.CheckConstraint( check=models.Q(price__gt=models.F("discounted_price")), name="price_gt_discounted_price", ), models.CheckConstraint( check=models.Q(price__gt=0), name="%(app_label)s_%(class)s_price_gt_0", ), models.CheckConstraint( check=models.Q( models.Q(unit__isnull=True) | models.Q(unit__in=["μg/mL", "ng/mL"]) ), name="unicode_unit_list", ), ] class UniqueConstraintProduct(models.Model): name = models.CharField(max_length=255) color = models.CharField(max_length=32, null=True) class Meta: constraints = [ models.UniqueConstraint(fields=["name", "color"], name="name_color_uniq"), ] class ChildUniqueConstraintProduct(UniqueConstraintProduct): pass class UniqueConstraintConditionProduct(models.Model): name = models.CharField(max_length=255) color = models.CharField(max_length=32, null=True) class Meta: required_db_features = {"supports_partial_indexes"} constraints = [ models.UniqueConstraint( fields=["name"], name="name_without_color_uniq", condition=models.Q(color__isnull=True), ), ] class UniqueConstraintDeferrable(models.Model): name = models.CharField(max_length=255) shelf = models.CharField(max_length=31) class Meta: required_db_features = { "supports_deferrable_unique_constraints", } constraints = [ models.UniqueConstraint( fields=["name"], name="name_init_deferred_uniq", deferrable=models.Deferrable.DEFERRED, ), models.UniqueConstraint( fields=["shelf"], name="sheld_init_immediate_uniq", deferrable=models.Deferrable.IMMEDIATE, ), ] class UniqueConstraintInclude(models.Model): name = models.CharField(max_length=255) color = models.CharField(max_length=32, null=True) class Meta: required_db_features = { "supports_table_check_constraints", "supports_covering_indexes", } constraints = [ models.UniqueConstraint( fields=["name"], name="name_include_color_uniq", include=["color"], ), ] class AbstractModel(models.Model): age = models.IntegerField() class Meta: abstract = True required_db_features = { "supports_table_check_constraints", } constraints = [ models.CheckConstraint( check=models.Q(age__gte=18), name="%(app_label)s_%(class)s_adult", ), ] class ChildModel(AbstractModel): pass class JSONFieldModel(models.Model): data = models.JSONField(null=True) class Meta: required_db_features = {"supports_json_field"}