221 lines
7.3 KiB
Markdown
221 lines
7.3 KiB
Markdown
# ormar
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<p>
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<a href="https://pypi.org/project/ormar">
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<img src="https://img.shields.io/pypi/v/ormar.svg" alt="Pypi version">
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</a>
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<a href="https://pypi.org/project/ormar">
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<img src="https://img.shields.io/pypi/pyversions/ormar.svg" alt="Pypi version">
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</a>
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<img src="https://github.com/collerek/ormar/workflows/build/badge.svg" alt="Build Status">
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<a href="https://codecov.io/gh/collerek/ormar">
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<img src="https://codecov.io/gh/collerek/ormar/branch/master/graph/badge.svg" alt="Coverage">
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</a>
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<a href="https://www.codefactor.io/repository/github/collerek/ormar">
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<img src="https://www.codefactor.io/repository/github/collerek/ormar/badge" alt="CodeFactor" />
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</a>
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<a href="https://app.codacy.com/manual/collerek/ormar?utm_source=github.com&utm_medium=referral&utm_content=collerek/oramr&utm_campaign=Badge_Grade_Dashboard">
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<img src="https://api.codacy.com/project/badge/Grade/62568734f70f49cd8ea7a1a0b2d0c107" alt="Codacy" />
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</a>
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</p>
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### Overview
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The `ormar` package is an async mini ORM for Python, with support for **Postgres,
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MySQL**, and **SQLite**.
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The main benefit of using `ormar` are:
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* getting an **async ORM that can be used with async frameworks** (fastapi, starlette etc.)
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* getting just **one model to maintain** - you don't have to maintain pydantic and other orm model (sqlalchemy, peewee, gino etc.)
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The goal was to create a simple ORM that can be **used directly (as request and response models) with [`fastapi`][fastapi]** that bases it's data validation on pydantic.
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Ormar - apart form obvious ORM in name - get it's name from ormar in swedish which means snakes, and ormar(e) in italian which means cabinet.
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And what's a better name for python ORM than snakes cabinet :)
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### Documentation
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Check out the [documentation][documentation] for details.
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### Dependencies
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Ormar is built with:
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* [`SQLAlchemy core`][sqlalchemy-core] for query building.
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* [`databases`][databases] for cross-database async support.
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* [`pydantic`][pydantic] for data validation.
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* typing_extensions for python 3.6 - 3.7
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### Migrations
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Because ormar is built on SQLAlchemy core, you can use [`alembic`][alembic] to provide
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database migrations.
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**ormar is still under development:** We recommend pinning any dependencies with `ormar~=0.4.0`
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### Quick Start
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**Note**: Use `ipython` to try this from the console, since it supports `await`.
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```python
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import databases
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import ormar
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import sqlalchemy
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database = databases.Database("sqlite:///db.sqlite")
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metadata = sqlalchemy.MetaData()
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class Album(ormar.Model):
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class Meta:
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tablename = "album"
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metadata = metadata
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database = database
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# note that type hints are optional so
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# id = ormar.Integer(primary_key=True)
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# is also valid
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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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class Track(ormar.Model):
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class Meta:
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tablename = "track"
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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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album: Optional[Album] = ormar.ForeignKey(Album)
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title: str = ormar.String(max_length=100)
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position: int = ormar.Integer()
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# Create some records to work with.
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malibu = await Album.objects.create(name="Malibu")
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await Track.objects.create(album=malibu, title="The Bird", position=1)
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await Track.objects.create(album=malibu, title="Heart don't stand a chance", position=2)
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await Track.objects.create(album=malibu, title="The Waters", position=3)
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# alternative creation of object divided into 2 steps
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fantasies = Album.objects.create(name="Fantasies")
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await fantasies.save()
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await Track.objects.create(album=fantasies, title="Help I'm Alive", position=1)
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await Track.objects.create(album=fantasies, title="Sick Muse", position=2)
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# Fetch an instance, without loading a foreign key relationship on it.
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track = await Track.objects.get(title="The Bird")
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# We have an album instance, but it only has the primary key populated
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print(track.album) # Album(id=1) [sparse]
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print(track.album.pk) # 1
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print(track.album.name) # None
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# Load the relationship from the database
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await track.album.load()
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assert track.album.name == "Malibu"
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# This time, fetch an instance, loading the foreign key relationship.
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track = await Track.objects.select_related("album").get(title="The Bird")
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assert track.album.name == "Malibu"
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# By default you also get a second side of the relation
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# constructed as lowercase source model name +'s' (tracks in this case)
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# you can also provide custom name with parameter related_name
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album = await Album.objects.select_related("tracks").all()
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assert len(album.tracks) == 3
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# Fetch instances, with a filter across an FK relationship.
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tracks = Track.objects.filter(album__name="Fantasies")
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assert len(tracks) == 2
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# Fetch instances, with a filter and operator across an FK relationship.
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tracks = Track.objects.filter(album__name__iexact="fantasies")
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assert len(tracks) == 2
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# Limit a query
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tracks = await Track.objects.limit(1).all()
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assert len(tracks) == 1
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```
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## Ormar Specification
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### QuerySet methods
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* `create(**kwargs): -> Model`
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* `get(**kwargs): -> Model`
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* `get_or_create(**kwargs) -> Model`
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* `update(each: bool = False, **kwargs) -> int`
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* `update_or_create(**kwargs) -> Model`
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* `bulk_create(objects: List[Model]) -> None`
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* `bulk_update(objects: List[Model], columns: List[str] = None) -> None`
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* `delete(each: bool = False, **kwargs) -> int`
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* `all(self, **kwargs) -> List[Optional[Model]]`
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* `filter(**kwargs) -> QuerySet`
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* `exclude(**kwargs) -> QuerySet`
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* `select_related(related: Union[List, str]) -> QuerySet`
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* `limit(limit_count: int) -> QuerySet`
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* `offset(offset: int) -> QuerySet`
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* `count() -> int`
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* `exists() -> bool`
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* `fields(columns: Union[List, str, set, dict]) -> QuerySet`
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* `exclude_fields(columns: Union[List, str, set, dict]) -> QuerySet`
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* `order_by(columns:Union[List, str]) -> QuerySet`
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#### Relation types
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* One to many - with `ForeignKey(to: Model)`
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* Many to many - with `ManyToMany(to: Model, through: Model)`
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#### Model fields types
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Available Model Fields (with required args - optional ones in docs):
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* `String(max_length)`
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* `Text()`
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* `Boolean()`
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* `Integer()`
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* `Float()`
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* `Date()`
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* `Time()`
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* `DateTime()`
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* `JSON()`
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* `BigInteger()`
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* `Decimal(scale, precision)`
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* `UUID()`
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* `ForeignKey(to)`
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* `ManyToMany(to, through)`
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### Available fields options
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The following keyword arguments are supported on all field types.
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* `primary_key: bool`
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* `nullable: bool`
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* `default: Any`
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* `server_default: Any`
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* `index: bool`
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* `unique: bool`
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* `choices: typing.Sequence`
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* `name: str`
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All fields are required unless one of the following is set:
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* `nullable` - Creates a nullable column. Sets the default to `None`.
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* `default` - Set a default value for the field.
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* `server_default` - Set a default value for the field on server side (like sqlalchemy's `func.now()`).
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* `primary key` with `autoincrement` - When a column is set to primary key and autoincrement is set on this column.
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Autoincrement is set by default on int primary keys.
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[sqlalchemy-core]: https://docs.sqlalchemy.org/en/latest/core/
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[databases]: https://github.com/encode/databases
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[pydantic]: https://pydantic-docs.helpmanual.io/
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[encode/orm]: https://github.com/encode/orm/
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[alembic]: https://alembic.sqlalchemy.org/en/latest/
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[fastapi]: https://fastapi.tiangolo.com/
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[documentation]: https://collerek.github.io/ormar/ |