bump version, update docs

README.md

@@ -154,7 +154,7 @@ assert len(tracks) == 1
 *  `bulk_create(objects: List[Model]) -> None`
 *  `bulk_update(objects: List[Model], columns: List[str] = None) -> None`
 *  `delete(each: bool = False, **kwargs) -> int`
-*  `all(self, **kwargs) -> List[Optional[Model]]`
+*  `all(**kwargs) -> List[Optional[Model]]`
 *  `filter(**kwargs) -> QuerySet`
 *  `exclude(**kwargs) -> QuerySet`
 *  `select_related(related: Union[List, str]) -> QuerySet`

docs/index.md

@@ -154,7 +154,7 @@ assert len(tracks) == 1
 *  `bulk_create(objects: List[Model]) -> None`
 *  `bulk_update(objects: List[Model], columns: List[str] = None) -> None`
 *  `delete(each: bool = False, **kwargs) -> int`
-*  `all(self, **kwargs) -> List[Optional[Model]]`
+*  `all(**kwargs) -> List[Optional[Model]]`
 *  `filter(**kwargs) -> QuerySet`
 *  `exclude(**kwargs) -> QuerySet`
 *  `select_related(related: Union[List, str]) -> QuerySet`

docs/queries.md

@@ -176,7 +176,7 @@ Return number of rows deleted.
 
 ### all
 
-`all(self, **kwargs) -> List[Optional["Model"]]`
+`all(**kwargs) -> List[Optional["Model"]]`
 
 Returns all rows from a database for given model for set filter options.
 

docs/relations.md

@@ -29,6 +29,83 @@ By default it's child (source) `Model` name + s, like courses in snippet below:
 --8<-- "../docs_src/fields/docs001.py"
 ```
 
+Reverse relation exposes API to manage related objects also from parent side.
+
+##### add
+
+Adding child model from parent side causes adding related model to currently loaded parent relation, 
+as well as sets child's model foreign key value and updates the model.
+
+```python
+department = await Department(name="Science").save()
+course = Course(name="Math", completed=False) # note - not saved
+
+await department.courses.add(course)
+assert course.pk is not None # child model was saved
+# relation on child model is set and FK column saved in db
+assert courses.department == department
+# relation on parent model is also set
+assert department.courses[0] == course 
+```
+
+!!!warning
+    If you want to add child model on related model the primary key value for parent model **has to exist in database**.
+    
+    Otherwise ormar will raise RelationshipInstanceError as it cannot set child's ForeignKey column value 
+    if parent model has no primary key value.
+    
+    That means that in example above the department has to be saved before you can call `department.courses.add()`.
+
+##### remove
+
+Removal of the related model one by one.
+
+In reverse relation calling `remove()` does not remove the child model, but instead nulls it ForeignKey value.
+
+```python
+# continuing from above
+await department.courses.remove(course)
+assert len(department.courses) == 0
+# course still exists and was saved in remove
+assert course.pk is not None
+assert course.department is None
+
+# to remove child from db
+await course.delete()
+```
+
+But if you want to clear the relation and delete the child at the same time you can issue:
+
+```python
+# this will not only clear the relation 
+# but also delete related course from db
+await department.courses.remove(course, keep_reversed=False)
+```
+
+##### clear
+
+Removal of all related models in one call.
+
+Like remove by default `clear()` nulls the ForeigKey column on child model (all, not matter if they are loaded or not).
+
+```python
+# nulls department column on all courses related to this department
+await department.courses.clear()
+```
+
+If you want to remove the children altogether from the database, set `keep_reversed=False`
+
+```python
+# deletes from db all courses related to this department 
+await department.courses.clear(keep_reversed=False)
+```
+
+##### QuerysetProxy
+
+Reverse relation exposes QuerysetProxy API that allows you to query related model like you would issue a normal Query.
+
+To read which methods of QuerySet are available read below [querysetproxy][querysetproxy]
+
 #### related_name
 
 But you can overwrite this name by providing `related_name` parameter like below:
@@ -94,7 +171,7 @@ Sqlalchemy column and Type are automatically taken from target `Model`.
 * Sqlalchemy column: class of a target `Model` primary key column  
 * Type (used for pydantic): type of a target `Model` 
 
-####Defining `Models`:
+####Defining `Models`
 
 ```Python
 --8<-- "../docs_src/relations/docs002.py"
@@ -107,7 +184,7 @@ post = await Post.objects.create(title="Hello, M2M", author=guido)
 news = await Category.objects.create(name="News")
 ```
 
-#### Adding related models
+#### add
 
 ```python
 # Add a category to a post.
@@ -121,7 +198,110 @@ await news.posts.add(post)
     
     Otherwise an IntegrityError will be raised by your database driver library.
 
-#### create()
+#### remove
+
+Removal of the related model one by one.
+
+Removes also the relation in the database.
+
+```python
+await news.posts.remove(post)
+```
+
+#### clear
+
+Removal of all related models in one call.
+
+Removes also the relation in the database.
+
+```python
+await news.posts.clear()
+```
+
+#### QuerysetProxy
+
+Reverse relation exposes QuerysetProxy API that allows you to query related model like you would issue a normal Query.
+
+To read which methods of QuerySet are available read below [querysetproxy][querysetproxy]
+
+### QuerySetProxy
+
+When access directly the related `ManyToMany` field as well as `ReverseForeignKey` returns the list of related models.
+
+But at the same time it exposes subset of QuerySet API, so you can filter, create, select related etc related models directly from parent model.
+
+!!!note
+    By default exposed QuerySet is already filtered to return only `Models` related to parent `Model`.
+    
+    So if you issue `post.categories.all()` you will get all categories related to that post, not all in table.
+
+!!!note
+    Note that when accessing QuerySet API methods through QuerysetProxy you don't 
+    need to use `objects` attribute like in normal queries.
+    
+    So note that it's `post.categories.all()` and **not** `post.categories.objects.all()`.
+    
+    To learn more about available QuerySet methods visit [queries][queries]
+
+!!!warning
+    Querying related models from ManyToMany cleans list of related models loaded on parent model:
+    
+    Example: `post.categories.first()` will set post.categories to list of 1 related model -> the one returned by first()
+    
+    Example 2: if post has 4 categories so `len(post.categories) == 4` calling `post.categories.limit(2).all()` 
+    -> will load only 2 children and now `assert len(post.categories) == 2`
+    
+    This happens for all QuerysetProxy methods returning data: `get`, `all` and `first` and in `get_or_create` if model already exists.
+    
+    Note that value returned by `create` or created in `get_or_create` and `update_or_create` 
+    if model does not exist will be added to relation list (not clearing it).
+
+#### get
+
+`get(**kwargs): -> Model` 
+
+To grab just one of related models filtered by name you can use `get(**kwargs)` method.
+
+```python
+# grab one category
+assert news == await post.categories.get(name="News")
+
+# note that method returns the category so you can grab this value
+# but it also modifies list of related models in place
+# so regardless of what was previously loaded on parent model
+# now it has only one value -> just loaded with get() call
+assert len(post.categories) == 1
+assert post.categories[0] == news
+
+```
+
+!!!tip
+    Read more in queries documentation [get][get]
+
+#### all
+
+`all(**kwargs) -> List[Optional["Model"]]`
+
+To get a list of related models use `all()` method. 
+
+Note that you can filter the queryset, select related, exclude fields etc. like in normal query.
+
+```python
+# with all Queryset methods - filtering, selecting columns, counting etc.
+await news.posts.filter(title__contains="M2M").all()
+await Category.objects.filter(posts__author=guido).get()
+
+# columns models of many to many relation can be prefetched
+news_posts = await news.posts.select_related("author").all()
+assert news_posts[0].author == guido
+```
+
+!!!tip
+    Read more in queries documentation [all][all]
+
+#### create
+
+`create(**kwargs): -> Model` 
 
 Create related `Model` directly from parent `Model`.
 
@@ -134,64 +314,117 @@ assert len(await post.categories.all()) == 2
 # newly created instance already have relation persisted in the database
 ```
 
-!!!note
+!!!tip
-    Note that when accessing QuerySet API methods through ManyToMany relation you don't 
+    Read more in queries documentation [create][create]
-    need to use objects attribute like in normal queries.
 
-    To learn more about available QuerySet methods visit [queries][queries]
 
-#### remove()
+#### get_or_create
 
-Removal of the related model one by one.
+`get_or_create(**kwargs) -> Model`
-
-Removes also the relation in the database.
-
-```python
-await news.posts.remove(post)
-```
-
-#### clear()
-
-Removal all related models in one call.
-
-Removes also the relation in the database.
-
-```python
-await news.posts.clear()
-```
-
-#### Other queryset methods
-
-When access directly the related `ManyToMany` field returns the list of related models.
-
-But at the same time it exposes full QuerySet API, so you can filter, create, select related etc.
-
-```python
-# Many to many relation exposes a list of columns models
-# and an API of the Queryset:
-assert news == await post.categories.get(name="News")
-
-# with all Queryset methods - filtering, selecting columns, counting etc.
-await news.posts.filter(title__contains="M2M").all()
-await Category.objects.filter(posts__author=guido).get()
-
-# columns models of many to many relation can be prefetched
-news_posts = await news.posts.select_related("author").all()
-assert news_posts[0].author == guido
-```
-
-Currently supported methods are:
 
 !!!tip
-    To learn more about available QuerySet methods visit [queries][queries]
+    Read more in queries documentation [get_or_create][get_or_create]
+
+#### update_or_create
+
+`update_or_create(**kwargs) -> Model`
+
+!!!tip
+    Read more in queries documentation [update_or_create][update_or_create]
+
+#### filter
+
+`filter(**kwargs) -> QuerySet`
+
+!!!tip
+    Read more in queries documentation [filter][filter]
+
+#### exclude
+
+`exclude(**kwargs) -> QuerySet`
+
+!!!tip
+    Read more in queries documentation [exclude][exclude]
+
+#### select_related
+
+`select_related(related: Union[List, str]) -> QuerySet`
+
+!!!tip
+    Read more in queries documentation [select_related][select_related]
+
+#### prefetch_related
+
+`prefetch_related(related: Union[List, str]) -> QuerySet`
+
+!!!tip
+    Read more in queries documentation [prefetch_related][prefetch_related]
+
+#### limit
+
+`limit(limit_count: int) -> QuerySet`
+
+!!!tip
+    Read more in queries documentation [limit][limit]
+
+#### offset
+
+`offset(offset: int) -> QuerySet`
+
+!!!tip
+    Read more in queries documentation [offset][offset]
+
+#### count
+
+`count() -> int`
+
+!!!tip
+    Read more in queries documentation [count][count]
+
+#### exists
+
+`exists() -> bool`
+
+!!!tip
+    Read more in queries documentation [exists][exists]
+
+#### fields
+
+`fields(columns: Union[List, str, set, dict]) -> QuerySet`
+
+!!!tip
+    Read more in queries documentation [fields][fields]
+
+#### exclude_fields
+
+`exclude_fields(columns: Union[List, str, set, dict]) -> QuerySet`
+
+!!!tip
+    Read more in queries documentation [exclude_fields][exclude_fields]
+
+#### order_by
+
+`order_by(columns:Union[List, str]) -> QuerySet`
+
+!!!tip
+    Read more in queries documentation [order_by][order_by]
 
-##### get()
-##### all()
-##### filter()
-##### select_related()
-##### limit()
-##### offset()
-##### count()
-##### exists()
 
 [queries]: ./queries.md
+[querysetproxy]: ./relations.md#querysetproxy-methods
+[get]: ./queries.md#get
+[all]: ./queries.md#all
+[create]: ./queries.md#create
+[get_or_create]: ./queries.md#get_or_create
+[update_or_create]: ./queries.md#update_or_create
+[filter]: ./queries.md#filter
+[exclude]: ./queries.md#exclude
+[select_related]: ./queries.md#select_related
+[prefetch_related]: ./queries.md#prefetch_related
+[limit]: ./queries.md#limit
+[offset]: ./queries.md#offset
+[count]: ./queries.md#count
+[exists]: ./queries.md#exists
+[fields]: ./queries.md#fields
+[exclude_fields]: ./queries.md#exclude_fields
+[order_by]: ./queries.md#order_by

docs/releases.md

@@ -1,3 +1,15 @@
+# 0.6.0
+
+*  **Breaking:** calling instance.load() when the instance row was deleted from db now raises ormar.NoMatch instead of ValueError
+*  **Breaking:** calling add and remove on ReverseForeignKey relation now updates the child model in db setting/removing fk column
+*  **Breaking:** ReverseForeignKey relation now exposes QuerySetProxy API like ManyToMany relation
+*  **Breaking:** querying related models from ManyToMany cleans list of related models loaded on parent model:
+    *  Example: `post.categories.first()` will set post.categories to list of 1 related model -> the one returned by first()
+    *  Example 2: if post has 4 categories so `len(post.categories) == 4` calling `post.categories.limit(2).all()` -> will load only 2 children and now `assert len(post.categories) == 2`
+*  Added `get_or_create`, `update_or_create`, `fields`, `exclude_fields`, `exclude`, `prefetch_related` and `order_by` to QuerySetProxy 
+so now you can use those methods directly from relation  
+*  Update docs
+
 # 0.5.5
 
 *  Fix for alembic autogenaration of migration `UUID` columns. It should just produce sqlalchemy `CHAR(32)` or `CHAR(36)`

docs_src/fields/docs001.py

@@ -29,7 +29,7 @@ class Course(ormar.Model):
     department: Optional[Department] = ormar.ForeignKey(Department)
 
 
-department = Department(name="Science")
+department = await Department(name="Science").save()
 course = Course(name="Math", completed=False, department=department)
 
 print(department.courses[0])

mkdocs.yml

@@ -1,5 +1,5 @@
 site_name: ormar
-site_description: An simple async ORM with fastapi in mind and pydantic validation.
+site_description: A simple async ORM with fastapi in mind and pydantic validation.
 nav:
   - Overview: index.md
   - Installation: install.md

ormar/__init__.py

@@ -30,7 +30,7 @@ class UndefinedType:  # pragma no cover
 
 Undefined = UndefinedType()
 
-__version__ = "0.5.5"
+__version__ = "0.6.0"
 __all__ = [
     "Integer",
     "BigInteger",

ormar/models/model.py

@@ -15,7 +15,7 @@ from typing import (
 import sqlalchemy
 
 import ormar.queryset  # noqa I100
-from ormar.exceptions import ModelPersistenceError
+from ormar.exceptions import ModelPersistenceError, NoMatch
 from ormar.fields.many_to_many import ManyToManyField
 from ormar.models import NewBaseModel  # noqa I100
 from ormar.models.metaclass import ModelMeta
@@ -286,9 +286,7 @@ class Model(NewBaseModel):
         expr = self.Meta.table.select().where(self.pk_column == self.pk)
         row = await self.Meta.database.fetch_one(expr)
         if not row:  # pragma nocover
-            raise ValueError(
+            raise NoMatch("Instance was deleted from database and cannot be refreshed")
-                "Instance was deleted from database and cannot be refreshed"
-            )
         kwargs = dict(row)
         kwargs = self.translate_aliases_to_columns(kwargs)
         self.from_dict(kwargs)

ormar/queryset/queryset.py

@@ -280,7 +280,9 @@ class QuerySet:
         return await self.database.fetch_val(expr)
 
     async def update(self, each: bool = False, **kwargs: Any) -> int:
-        self_fields = self.model.extract_db_own_fields()
+        self_fields = self.model.extract_db_own_fields().union(
+            self.model.extract_related_names()
+        )
         updates = {k: v for k, v in kwargs.items() if k in self_fields}
         updates = self.model.translate_columns_to_aliases(updates)
         if not each and not self.filter_clauses:

ormar/relations/querysetproxy.py

@@ -88,7 +88,7 @@ class QuerysetProxy(ormar.QuerySetProtocol):
     async def count(self) -> int:
         return await self.queryset.count()
 
-    async def clear(self) -> int:
+    async def clear(self, keep_reversed: bool = True) -> int:
         if self.type_ == ormar.RelationType.MULTIPLE:
             queryset = ormar.QuerySet(model_cls=self.relation.through)
             owner_column = self._owner.get_name()
@@ -97,10 +97,16 @@ class QuerysetProxy(ormar.QuerySetProtocol):
             owner_column = self.related_field.name
         kwargs = {owner_column: self._owner}
         self._clean_items_on_load()
+        if keep_reversed and self.type_ == ormar.RelationType.REVERSE:
+            update_kwrgs = {f"{owner_column}": None}
+            return await queryset.filter(_exclude=False, **kwargs).update(
+                each=False, **update_kwrgs
+            )
         return await queryset.delete(**kwargs)  # type: ignore
 
     async def first(self, **kwargs: Any) -> "Model":
         first = await self.queryset.first(**kwargs)
+        self._clean_items_on_load()
         self._register_related(first)
         return first
 

ormar/relations/relation_proxy.py

@@ -38,17 +38,20 @@ class RelationProxy(list):
             and self.queryset_proxy.queryset is not None
         )
 
-    def _set_queryset(self) -> "QuerySet":
+    def _check_if_model_saved(self) -> None:
-        related_field = self._owner.resolve_relation_field(
-            self.relation.to, self._owner
-        )
-        pkname = self._owner.get_column_alias(self._owner.Meta.pkname)
         pk_value = self._owner.pk
         if not pk_value:
             raise RelationshipInstanceError(
                 "You cannot query relationships from unsaved model."
             )
-        kwargs = {f"{related_field.get_alias()}__{pkname}": pk_value}
+
+    def _set_queryset(self) -> "QuerySet":
+        related_field = self._owner.resolve_relation_field(
+            self.relation.to, self._owner
+        )
+        pkname = self._owner.get_column_alias(self._owner.Meta.pkname)
+        self._check_if_model_saved()
+        kwargs = {f"{related_field.get_alias()}__{pkname}": self._owner.pk}
         queryset = (
             ormar.QuerySet(model_cls=self.relation.to)
             .select_related(related_field.name)
@@ -56,7 +59,9 @@ class RelationProxy(list):
         )
         return queryset
 
-    async def remove(self, item: "Model") -> None:  # type: ignore
+    async def remove(  # type: ignore
+        self, item: "Model", keep_reversed: bool = True
+    ) -> None:
         if item not in self:
             raise NoMatch(
                 f"Object {self._owner.get_name()} has no "
@@ -74,8 +79,11 @@ class RelationProxy(list):
         if self.type_ == ormar.RelationType.MULTIPLE:
             await self.queryset_proxy.delete_through_instance(item)
         else:
+            if keep_reversed:
                 setattr(item, rel_name, None)
                 await item.update()
+            else:
+                await item.delete()
 
     async def add(self, item: "Model") -> None:
         if self.type_ == ormar.RelationType.MULTIPLE:
@@ -83,6 +91,7 @@ class RelationProxy(list):
             rel_name = item.resolve_relation_name(item, self._owner)
             setattr(item, rel_name, self._owner)
         else:
+            self._check_if_model_saved()
             related_field = self._owner.resolve_relation_field(
                 self.relation.to, self._owner
             )

tests/test_reverse_fk_queryset.py

@@ -5,6 +5,7 @@ import pytest
 import sqlalchemy
 
 import ormar
+from ormar import NoMatch
 from tests.settings import DATABASE_URL
 
 database = databases.Database(DATABASE_URL, force_rollback=True)
@@ -190,6 +191,26 @@ async def test_getting():
             assert len(tracks) == 0
             assert len(album.tracks) == 0
 
+            still_tracks = await Track.objects.all()
+            assert len(still_tracks) == 4
+            for track in still_tracks:
+                assert track.album is None
+
+
+@pytest.mark.asyncio
+async def test_cleaning_related():
+    async with database:
+        async with database.transaction(force_rollback=True):
+            sample_data = await get_sample_data()
+            album = sample_data[0]
+            await album.tracks.clear(keep_reversed=False)
+            tracks = await album.tracks.all()
+            assert len(tracks) == 0
+            assert len(album.tracks) == 0
+
+            no_tracks = await Track.objects.all()
+            assert len(no_tracks) == 0
+
 
 @pytest.mark.asyncio
 async def test_loading_related():
@@ -224,12 +245,14 @@ async def test_adding_removing():
             track_check = await Track.objects.get(title="Rainbow")
             assert track_check.album == album
 
-            track_test = await Track.objects.get(title="Rainbow")
-            assert track_test.album == album
-
             await album.tracks.remove(track_new)
             assert track_new.album is None
             assert len(album.tracks) == 3
 
+            track1 = album.tracks[0]
+            await album.tracks.remove(track1, keep_reversed=False)
+            with pytest.raises(NoMatch):
+                await track1.load()
+
             track_test = await Track.objects.get(title="Rainbow")
             assert track_test.album is None