69 lines
2.9 KiB
Python
69 lines
2.9 KiB
Python
import databases
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import sqlalchemy
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import ormar
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from tests.settings import DATABASE_URL
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database = databases.Database(DATABASE_URL, force_rollback=True)
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metadata = sqlalchemy.MetaData()
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class Company(ormar.Model):
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class Meta:
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tablename = "companies"
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metadata = metadata
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database = database
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id: int = ormar.Integer(primary_key=True)
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name: str = ormar.String(max_length=100)
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founded: int = ormar.Integer(nullable=True)
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class Car(ormar.Model):
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class Meta:
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tablename = "cars"
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metadata = metadata
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database = database
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id: int = ormar.Integer(primary_key=True)
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manufacturer = ormar.ForeignKey(Company)
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name: str = ormar.String(max_length=100)
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year: int = ormar.Integer(nullable=True)
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gearbox_type: str = ormar.String(max_length=20, nullable=True)
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gears: int = ormar.Integer(nullable=True)
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aircon_type: str = ormar.String(max_length=20, nullable=True)
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# build some sample data
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toyota = await Company.objects.create(name="Toyota", founded=1937)
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await Car.objects.create(manufacturer=toyota, name="Corolla", year=2020, gearbox_type='Manual', gears=5,
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aircon_type='Manual')
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await Car.objects.create(manufacturer=toyota, name="Yaris", year=2019, gearbox_type='Manual', gears=5,
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aircon_type='Manual')
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await Car.objects.create(manufacturer=toyota, name="Supreme", year=2020, gearbox_type='Auto', gears=6,
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aircon_type='Auto')
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# select manufacturer but only name - to include related models use notation {model_name}__{column}
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all_cars = await Car.objects.select_related('manufacturer').exclude_fields(
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['year', 'gearbox_type', 'gears', 'aircon_type', 'company__founded']).all()
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for car in all_cars:
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# excluded columns will yield None
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assert all(getattr(car, x) is None for x in ['year', 'gearbox_type', 'gears', 'aircon_type'])
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# included column on related models will be available, pk column is always included
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# even if you do not include it in fields list
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assert car.manufacturer.name == 'Toyota'
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# also in the nested related models - you cannot exclude pk - it's always auto added
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assert car.manufacturer.founded is None
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# fields() can be called several times, building up the columns to select
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# models selected in select_related but with no columns in fields list implies all fields
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all_cars = await Car.objects.select_related('manufacturer').exclude_fields('year').exclude_fields(
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['gear', 'gearbox_type']).all()
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# all fiels from company model are selected
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assert all_cars[0].manufacturer.name == 'Toyota'
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assert all_cars[0].manufacturer.founded == 1937
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# cannot exclude mandatory model columns - company__name in this example - note usage of dict/set this time
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await Car.objects.select_related('manufacturer').exclude_fields([{'company': {'name'}}]).all()
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# will raise pydantic ValidationError as company.name is required
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