feat: bring first() to parity with get()/get_or_none() — add with_for_update and schema support (#123)

2026-04-16 06:36:26 +02:00 · 2026-03-10 19:34:18 +01:00
parent 4800941934
commit e4250a9910
3 changed files with 286 additions and 9 deletions
--- a/docs/module/crud.md
+++ b/docs/module/crud.md
@@ -29,6 +29,9 @@ user = await UserCrud.create(session=session, obj=UserCreateSchema(username="ali
 # Get one (raises NotFoundError if not found)
 user = await UserCrud.get(session=session, filters=[User.id == user_id])

+# Get one or None (never raises)
+user = await UserCrud.get_or_none(session=session, filters=[User.id == user_id])
+
 # Get first or None
 user = await UserCrud.first(session=session, filters=[User.email == email])

@@ -46,6 +49,36 @@ count = await UserCrud.count(session=session, filters=[User.is_active == True])
 exists = await UserCrud.exists(session=session, filters=[User.email == email])
 ```

+## Fetching a single record
+
+Three methods fetch a single record — choose based on how you want to handle the "not found" case and whether you need strict uniqueness:
+
+| Method | Not found | Multiple results |
+|---|---|---|
+| `get` | raises `NotFoundError` | raises `MultipleResultsFound` |
+| `get_or_none` | returns `None` | raises `MultipleResultsFound` |
+| `first` | returns `None` | returns the first match silently |
+
+Use `get` when the record must exist (e.g. a detail endpoint that should return 404):
+
+```python
+user = await UserCrud.get(session=session, filters=[User.id == user_id])
+```
+
+Use `get_or_none` when the record may not exist but you still want strict uniqueness enforcement:
+
+```python
+user = await UserCrud.get_or_none(session=session, filters=[User.email == email])
+if user is None:
+    ...  # handle missing case without catching an exception
+```
+
+Use `first` when you only care about any one match and don't need uniqueness:
+
+```python
+user = await UserCrud.first(session=session, filters=[User.is_active == True])
+```
+
 ## Pagination

 !!! info "Added in `v1.1` (only offset_pagination via `paginate` if `<v1.1`)"
--- a/src/fastapi_toolsets/crud/factory.py
+++ b/src/fastapi_toolsets/crud/factory.py
@@ -409,6 +409,82 @@ class AsyncCrud(Generic[ModelType]):
            NotFoundError: If no record found
            MultipleResultsFound: If more than one record found
        """
+        result = await cls.get_or_none(
+            session,
+            filters,
+            joins=joins,
+            outer_join=outer_join,
+            with_for_update=with_for_update,
+            load_options=load_options,
+            schema=schema,
+        )
+        if result is None:
+            raise NotFoundError()
+        return result
+
+    @overload
+    @classmethod
+    async def get_or_none(  # pragma: no cover
+        cls: type[Self],
+        session: AsyncSession,
+        filters: list[Any],
+        *,
+        joins: JoinType | None = None,
+        outer_join: bool = False,
+        with_for_update: bool = False,
+        load_options: list[ExecutableOption] | None = None,
+        schema: type[SchemaType],
+    ) -> Response[SchemaType] | None: ...
+
+    @overload
+    @classmethod
+    async def get_or_none(  # pragma: no cover
+        cls: type[Self],
+        session: AsyncSession,
+        filters: list[Any],
+        *,
+        joins: JoinType | None = None,
+        outer_join: bool = False,
+        with_for_update: bool = False,
+        load_options: list[ExecutableOption] | None = None,
+        schema: None = ...,
+    ) -> ModelType | None: ...
+
+    @classmethod
+    async def get_or_none(
+        cls: type[Self],
+        session: AsyncSession,
+        filters: list[Any],
+        *,
+        joins: JoinType | None = None,
+        outer_join: bool = False,
+        with_for_update: bool = False,
+        load_options: list[ExecutableOption] | None = None,
+        schema: type[BaseModel] | None = None,
+    ) -> ModelType | Response[Any] | None:
+        """Get exactly one record, or ``None`` if not found.
+
+        Like :meth:`get` but returns ``None`` instead of raising
+        :class:`~fastapi_toolsets.exceptions.NotFoundError` when no record
+        matches the filters.
+
+        Args:
+            session: DB async session
+            filters: List of SQLAlchemy filter conditions
+            joins: List of (model, condition) tuples for joining related tables
+            outer_join: Use LEFT OUTER JOIN instead of INNER JOIN
+            with_for_update: Lock the row for update
+            load_options: SQLAlchemy loader options (e.g., selectinload)
+            schema: Pydantic schema to serialize the result into. When provided,
+                the result is automatically wrapped in a ``Response[schema]``.
+
+        Returns:
+            Model instance, ``Response[schema]`` when ``schema`` is given,
+            or ``None`` when no record matches.
+
+        Raises:
+            MultipleResultsFound: If more than one record found
+        """
        q = select(cls.model)
        q = _apply_joins(q, joins, outer_join)
        q = q.where(and_(*filters))
@@ -418,12 +494,40 @@ class AsyncCrud(Generic[ModelType]):
            q = q.with_for_update()
        result = await session.execute(q)
        item = result.unique().scalar_one_or_none()
-        if not item:
-            raise NotFoundError()
-        result = cast(ModelType, item)
+        if item is None:
+            return None
+        db_model = cast(ModelType, item)
        if schema:
-            return Response(data=schema.model_validate(result))
-        return result
+            return Response(data=schema.model_validate(db_model))
+        return db_model
+
+    @overload
+    @classmethod
+    async def first(  # pragma: no cover
+        cls: type[Self],
+        session: AsyncSession,
+        filters: list[Any] | None = None,
+        *,
+        joins: JoinType | None = None,
+        outer_join: bool = False,
+        with_for_update: bool = False,
+        load_options: list[ExecutableOption] | None = None,
+        schema: type[SchemaType],
+    ) -> Response[SchemaType] | None: ...
+
+    @overload
+    @classmethod
+    async def first(  # pragma: no cover
+        cls: type[Self],
+        session: AsyncSession,
+        filters: list[Any] | None = None,
+        *,
+        joins: JoinType | None = None,
+        outer_join: bool = False,
+        with_for_update: bool = False,
+        load_options: list[ExecutableOption] | None = None,
+        schema: None = ...,
+    ) -> ModelType | None: ...

    @classmethod
    async def first(
@@ -433,8 +537,10 @@ class AsyncCrud(Generic[ModelType]):
        *,
        joins: JoinType | None = None,
        outer_join: bool = False,
+        with_for_update: bool = False,
        load_options: list[ExecutableOption] | None = None,
-    ) -> ModelType | None:
+        schema: type[BaseModel] | None = None,
+    ) -> ModelType | Response[Any] | None:
        """Get the first matching record, or None.

        Args:
@@ -442,10 +548,14 @@ class AsyncCrud(Generic[ModelType]):
            filters: List of SQLAlchemy filter conditions
            joins: List of (model, condition) tuples for joining related tables
            outer_join: Use LEFT OUTER JOIN instead of INNER JOIN
-            load_options: SQLAlchemy loader options
+            with_for_update: Lock the row for update
+            load_options: SQLAlchemy loader options (e.g., selectinload)
+            schema: Pydantic schema to serialize the result into. When provided,
+                the result is automatically wrapped in a ``Response[schema]``.

        Returns:
-            Model instance or None
+            Model instance, ``Response[schema]`` when ``schema`` is given,
+            or ``None`` when no record matches.
        """
        q = select(cls.model)
        q = _apply_joins(q, joins, outer_join)
@@ -453,8 +563,16 @@ class AsyncCrud(Generic[ModelType]):
            q = q.where(and_(*filters))
        if resolved := cls._resolve_load_options(load_options):
            q = q.options(*resolved)
+        if with_for_update:
+            q = q.with_for_update()
        result = await session.execute(q)
-        return cast(ModelType | None, result.unique().scalars().first())
+        item = result.unique().scalars().first()
+        if item is None:
+            return None
+        db_model = cast(ModelType, item)
+        if schema:
+            return Response(data=schema.model_validate(db_model))
+        return db_model

    @classmethod
    async def get_multi(
--- a/tests/test_crud.py
+++ b/tests/test_crud.py
@@ -295,6 +295,100 @@ class TestCrudGet:
        assert user.username == "active"


+class TestCrudGetOrNone:
+    """Tests for CRUD get_or_none operations."""
+
+    @pytest.mark.anyio
+    async def test_returns_record_when_found(self, db_session: AsyncSession):
+        """get_or_none returns the record when it exists."""
+        created = await RoleCrud.create(db_session, RoleCreate(name="admin"))
+        fetched = await RoleCrud.get_or_none(db_session, [Role.id == created.id])
+
+        assert fetched is not None
+        assert fetched.id == created.id
+        assert fetched.name == "admin"
+
+    @pytest.mark.anyio
+    async def test_returns_none_when_not_found(self, db_session: AsyncSession):
+        """get_or_none returns None instead of raising NotFoundError."""
+        result = await RoleCrud.get_or_none(db_session, [Role.id == uuid.uuid4()])
+        assert result is None
+
+    @pytest.mark.anyio
+    async def test_with_schema_returns_response_when_found(
+        self, db_session: AsyncSession
+    ):
+        """get_or_none with schema returns Response[schema] when found."""
+        from fastapi_toolsets.schemas import Response
+
+        created = await RoleCrud.create(db_session, RoleCreate(name="editor"))
+        result = await RoleCrud.get_or_none(
+            db_session, [Role.id == created.id], schema=RoleRead
+        )
+
+        assert isinstance(result, Response)
+        assert isinstance(result.data, RoleRead)
+        assert result.data.name == "editor"
+
+    @pytest.mark.anyio
+    async def test_with_schema_returns_none_when_not_found(
+        self, db_session: AsyncSession
+    ):
+        """get_or_none with schema returns None (not Response) when not found."""
+        result = await RoleCrud.get_or_none(
+            db_session, [Role.id == uuid.uuid4()], schema=RoleRead
+        )
+        assert result is None
+
+    @pytest.mark.anyio
+    async def test_with_load_options(self, db_session: AsyncSession):
+        """get_or_none respects load_options."""
+        from sqlalchemy.orm import selectinload
+
+        role = await RoleCrud.create(db_session, RoleCreate(name="member"))
+        user = await UserCrud.create(
+            db_session,
+            UserCreate(username="alice", email="alice@test.com", role_id=role.id),
+        )
+
+        fetched = await UserCrud.get_or_none(
+            db_session,
+            [User.id == user.id],
+            load_options=[selectinload(User.role)],
+        )
+
+        assert fetched is not None
+        assert fetched.role is not None
+        assert fetched.role.name == "member"
+
+    @pytest.mark.anyio
+    async def test_with_join(self, db_session: AsyncSession):
+        """get_or_none respects joins."""
+        user = await UserCrud.create(
+            db_session, UserCreate(username="author", email="author@test.com")
+        )
+        await PostCrud.create(
+            db_session,
+            PostCreate(title="Published", author_id=user.id, is_published=True),
+        )
+
+        fetched = await UserCrud.get_or_none(
+            db_session,
+            [User.id == user.id, Post.is_published == True],  # noqa: E712
+            joins=[(Post, Post.author_id == User.id)],
+        )
+        assert fetched is not None
+        assert fetched.id == user.id
+
+        # Filter that matches no join — returns None
+        missing = await UserCrud.get_or_none(
+            db_session,
+            [User.id == user.id, Post.is_published == False],  # noqa: E712
+            joins=[(Post, Post.author_id == User.id)],
+        )
+        assert missing is None
+
+
 class TestCrudFirst:
    """Tests for CRUD first operations."""

@@ -322,6 +416,38 @@ class TestCrudFirst:
        role = await RoleCrud.first(db_session)
        assert role is not None

+    @pytest.mark.anyio
+    async def test_first_with_schema(self, db_session: AsyncSession):
+        """First with schema returns a Response wrapping the serialized record."""
+        await RoleCrud.create(db_session, RoleCreate(name="admin"))
+
+        result = await RoleCrud.first(
+            db_session, [Role.name == "admin"], schema=RoleRead
+        )
+
+        assert result is not None
+        assert result.data is not None
+        assert result.data.name == "admin"
+
+    @pytest.mark.anyio
+    async def test_first_with_schema_not_found(self, db_session: AsyncSession):
+        """First with schema returns None when no record matches."""
+        result = await RoleCrud.first(
+            db_session, [Role.name == "ghost"], schema=RoleRead
+        )
+        assert result is None
+
+    @pytest.mark.anyio
+    async def test_first_with_for_update(self, db_session: AsyncSession):
+        """First with with_for_update locks the row."""
+        await RoleCrud.create(db_session, RoleCreate(name="admin"))
+
+        role = await RoleCrud.first(
+            db_session, [Role.name == "admin"], with_for_update=True
+        )
+        assert role is not None
+        assert role.name == "admin"
+

 class TestCrudGetMulti:
    """Tests for CRUD get_multi operations."""