sqla-filter 0.3.0

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

Filter 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
    author_user_id: Annotated[
        UUID | Unset,
        FilterField(
            User.id,
            operator=eq,
            relationships=[
                RelationshipInfo(field=Book.authors),
                RelationshipInfo(field=Author.user),
            ],
        ),
    ] = 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()

Ordering example

from typing import Annotated, Any

from sqlalchemy import Select, select

from examples.models import Author, Book, User
from sqla_filter import (
    UNSET,
    BaseSorter,
    OrderingEnum,
    OrderingField,
    RelationshipInfo,
    Unset,
)
from sqla_filter.ordering import build_priorities


class BookSorter(BaseSorter):
    created_at: Annotated[OrderingEnum | Unset, OrderingField(Book.created_at)] = UNSET
    author_user_first_name: Annotated[
        OrderingEnum | Unset,
        OrderingField(
            User.first_name,
            relationships=[
                RelationshipInfo(field=Book.authors),
                RelationshipInfo(field=Author.user),
            ],
        ),
    ] = UNSET
    author_user_last_name: Annotated[
        OrderingEnum | Unset,
        OrderingField(
            User.last_name,
            relationships=[
                RelationshipInfo(field=Book.authors),
                RelationshipInfo(field=Author.user),
            ],
        ),
    ] = UNSET
    author_user_last_name_nulls_last: Annotated[
        OrderingEnum | Unset,
        OrderingField(
            User.last_name,
            relationships=[
                RelationshipInfo(field=Book.authors),
                RelationshipInfo(field=Author.user),
            ],
        ),
        nulls="last",
    ] = UNSET
    author_user_is_deleted: Annotated[
        OrderingEnum | Unset,
        OrderingField(
            User.is_deleted,
            relationships=[
                RelationshipInfo(field=Book.authors),
                RelationshipInfo(field=Author.user),
            ],
        ),
    ] = UNSET


def main() -> None:
    stmt = select(Book)
    print_stmt(stmt)

    sorter = BookSorter(
        author_user_last_name=OrderingEnum.desc,
        created_at=OrderingEnum.desc,
        author_user_is_deleted=OrderingEnum.desc,
    )

    stmt = sorter.apply(
        stmt,
        fields_priority=build_priorities(
            BookSorter.author_user_is_deleted,
            BookSorter.author_user_last_name,
        ),
    )
    print_stmt(stmt)


def print_stmt(stmt: Select[tuple[Any, ...]]) -> None:
    from sqlalchemy.dialects import postgresql

    print(  # noqa: T201
        stmt.compile(
            dialect=postgresql.dialect(),  # type: ignore[no-untyped-call]
            compile_kwargs={
                "literal_binds": True,
            },
        ),
        "\n",
    )


if __name__ == "__main__":
    main()

Important note: Only pass fields of a class that extends the BaseSorter class to build_priorities.

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

All examples are available at the following link