sqla-filter 0.1.4

Type safety filter for SQLAlchemy

SQLAlchemy Filter

Package for convenient filtering functionality in SQLAlchemy

Quite often, optional filtering functionality is required. To facilitate the implementation of filtering functionality, this package was written

Example:

# db/models.py
class Review(Base):
    __tablename__ = "review"

    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4)
    content: Mapped[str]
    book_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("book.id"))
    user_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("user.id"))


class Author(Base):
    __tablename__ = "author"

    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4)


class BookAuthor(Base):
    __tablename__ = "book__author"

    book_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("book.id"), primary_key=True)
    author_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("author.id"),
        primary_key=True,
    )


class Book(Base):
    __tablename__ = "book"

    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4)
    authors: Mapped[list[Author]] = relationship(secondary=BookAuthor.__table__)
    reviews: Mapped[list[Review]] = relationship()
    created_at: Mapped[datetime]

This is how it was before:

# core/domain/book/dto.py
@dataclass(frozen=True, slots=True)
class BookFilter:
    ident: UUID | None = None
    created_at_from: datetime | None = None
    created_at_to: datetime | None = None

    author_ids: Sequence[UUID] | None = None
    review_ids: Sequence[UUID] | None = None

    review_content_contains: str | None = None


# core/domain/book/repository.py
class BookRepository:
    ...

    async def get_list(self, filter_: BookFilter) -> Sequence[Book]:
        stmt = select(Book)

        if filter_.ident is not None:
            stmt = stmt.where(Book.id == filter_.ident)
        if filter_.created_at_from is not None:
            stmt = stmt.where(Book.created_at >= filter_.created_at_from)
        if filter_.created_at_to is not None:
            stmt = stmt.where(Book.created_at <= filter_.created_at_to)
        if filter_.author_ids is not None:
            stmt = stmt.join(Book.authors).where(Author.id.in_(filter_.author_ids))
        if filter_.review_ids is not None:
            stmt = stmt.join(Book.reviews).where(Review.id.in_(filter_.review_ids))

        return (await self._session.scalars(stmt)).all()

And here's how after using the package:

# core/domain/book/dto.py
from sqlalchemy.sql.operators import eq, ge, icontains_op, in_op, le
from sqla_filter import (
    BaseFilter,
    Unset,
    UNSET,
    FilterField,
    RelationshipInfo,
)


class BookFilter(BaseFilter):
    ident: Annotated[UUID | Unset, FilterField(Book.id, operator=eq)] = UNSET

    created_at_from: Annotated[
        datetime | Unset,
        FilterField(Book.created_at, operator=ge),
    ] = UNSET
    created_at_to: Annotated[
        datetime | Unset,
        FilterField(Book.created_at, operator=le),
    ] = UNSET

    author_ids: Annotated[
        Sequence[UUID] | Unset,
        FilterField(
            Author.id,
            operator=in_op,
            relationship=RelationshipInfo(field=Book.authors),
        ),
    ] = UNSET
    review_ids: Annotated[
        list[UUID] | Unset,
        FilterField(
            Review.id,
            operator=in_op,
            relationship=RelationshipInfo(field=Book.reviews),
        ),
    ] = UNSET
    review_content_contains: Annotated[
        str | Unset,
        FilterField(
            Review.content,
            operator=icontains_op,
            relationship=RelationshipInfo(field=Book.reviews),
        ),
    ] = UNSET


# core/domain/book/repository.py
class BookRepository:
    ...

    async def get_list(self, filter_: BookFilter) -> Sequence[Book]:
        stmt = select(Book)
        stmt = filter_.apply(stmt)
        return (await self._session.scalars(stmt)).all()

If the field is set to "NOT_SET", the filter will not be applied.

The entire example is available at this link