SQLAlchemy plugin for PyCharm

Disclaimer

I am a python dev with literally zero Java/Kotlin background, while this plugin hasn't burnt down my house yet, I have no confidence it won't in the future. USE AT YOUR OWN RISK

Features

Adds type support for model instance attributes:

class Entity(DeclarativeBase):
    status: Mapped[str] = mapped_column("status", String)

entity = Entity()
entity.status = "active"    # Correct
entity.status = 10          # Warning: Expected type 'str', got 'int' instead

Breaks type support for equality comparisons with class attributes. (Fixed for EAP builds, unfortunately solution relies on type checker extension point introduced in EAP builds.)

class Entity(DeclarativeBase):
    status: Mapped[str] = mapped_column("status", String)

query = (
    select(Entity)
    .filter(Entity.status == "active")  # Warning: Expected type 'ColumnElement[bool]', got 'bool' instead
)

query = (
    select(Entity)
    .filter("active" == Entity.status)  # No warning, pycharm has a bug (see PY-24960).
)

Improve support for @declared_attr and @hybrid_property

class StatusMixin:
    @declared_attr
    def status(cls) -> Mapped[str]:
        return mapped_column("status", String)

class User(StatusMixin, DeclarativeBase):
    @hybrid_property
    def is_active(self) -> bool:
        return self.status in ("active", "verified")
    
    @is_active.expression
    def is_active(cls) -> ColumnElement[bool]:
        return cls.status.in_(("active", "verified"))

user = User()
is_active: bool = user.is_active
user.status = "active"      # Correct
user.status = 10            # Warning: Expected type 'str', got 'int' instead

See example_project for more examples.

Installation

The plugin is not uploaded to JetBrains plugin registry (yet), instead you have to install from disk. The following options are available:

1. Download a build from the builds directory.
2. Clone the repository and use the buildPlugin gradle task. The build will be in the build/distributions directory.

The oldest version supported is 2023.3, if you want to use an older release try to change gradle.properties before building.

Feature Requests

I started this plugin as a weekend project, I have no plan what-so-ever for it's continued development or support. However, if you got an idea for a feature, feel free to open an issue.

Some features I want to work on:

1. Conversion of v1 style column definitions to v2, i.e. status = Column("status", String) to status: Mapped[str] = mapped_column("status", String)
2. Inspection/Conversion for explicitly specifying column name, i.e. use status: Mapped[str] = mapped_column("status", String()) instead of status: Mapped[str] = mapped_column(String()).
3. Inspection for matching database schema with alchemy definitions when using data sources.

Acknowledgements

Special thanks to the creators of pydantic-pycharm-plugin which I used as a reference.