update readme, bump version

README.md

@@ -264,6 +264,52 @@ await news.posts.clear()
 
 ```
 
+Since version >=0.3.4 Ormar supports also queryset level delete and update statements
+```python
+import databases
+import ormar
+import sqlalchemy
+
+database = databases.Database("sqlite:///db.sqlite")
+metadata = sqlalchemy.MetaData()
+
+class Book(ormar.Model):
+    class Meta:
+        tablename = "books"
+        metadata = metadata
+        database = database
+
+    id: ormar.Integer(primary_key=True)
+    title: ormar.String(max_length=200)
+    author: ormar.String(max_length=100)
+    genre: ormar.String(max_length=100, default='Fiction', choices=['Fiction', 'Adventure', 'Historic', 'Fantasy'])
+
+await Book.objects.create(title='Tom Sawyer', author="Twain, Mark", genre='Adventure')
+await Book.objects.create(title='War and Peace', author="Tolstoy, Leo", genre='Fiction')
+await Book.objects.create(title='Anna Karenina', author="Tolstoy, Leo", genre='Fiction')
+await Book.objects.create(title='Harry Potter', author="Rowling, J.K.", genre='Fantasy')
+await Book.objects.create(title='Lord of the Rings', author="Tolkien, J.R.", genre='Fantasy')
+
+# update accepts kwargs that are used to update queryset model
+# all other arguments are ignored (argument names not in own model table)
+await Book.objects.filter(author="Tolstoy, Leo").update(author="Lenin, Vladimir") # update all Tolstoy's books
+all_books = await Book.objects.filter(author="Lenin, Vladimir").all()
+assert len(all_books) == 2
+
+# delete accepts kwargs that will be used in filter
+# acting in same way as queryset.filter(**kwargs).delete()
+await Book.objects.delete(genre='Fantasy') # delete all fantasy books
+all_books = await Book.objects.all()
+assert len(all_books) == 3
+
+# queryset needs to be filtered before deleting to prevent accidental overwrite
+# to update whole database table each=True needs to be provided as a safety switch
+await Book.objects.update(each=True, genre='Fiction')
+all_books = await Book.objects.filter(genre='Fiction').all()
+assert len(all_books) == 3
+
+```
+
 ## Data types
 
 The following keyword arguments are supported on all field types.

ormar/__init__.py

@@ -26,7 +26,7 @@ class UndefinedType:  # pragma no cover
 
 Undefined = UndefinedType()
 
-__version__ = "0.3.3"
+__version__ = "0.3.4"
 __all__ = [
     "Integer",
     "BigInteger",

ormar/models/modelproxy.py

@@ -28,7 +28,9 @@ class ModelTableProxy:
     @classmethod
     def extract_db_own_fields(cls) -> set:
         related_names = cls._extract_related_names()
-        self_fields = {name for name in cls.Meta.model_fields.keys() if name not in related_names}
+        self_fields = {
+            name for name in cls.Meta.model_fields.keys() if name not in related_names
+        }
         return self_fields
 
     @classmethod

ormar/queryset/queryset.py

@@ -140,20 +140,23 @@ class QuerySet:
         self_fields = self.model_cls.extract_db_own_fields()
         updates = {k: v for k, v in kwargs.items() if k in self_fields}
         if not each and not self.filter_clauses:
-            raise QueryDefinitionError('You cannot update without filtering the queryset first. '
+            raise QueryDefinitionError(
-                                       'If you want to update all rows use update(each=True, **kwargs)')
+                "You cannot update without filtering the queryset first. "
+                "If you want to update all rows use update(each=True, **kwargs)"
+            )
         expr = FilterQuery(filter_clauses=self.filter_clauses).apply(
             self.table.update().values(**updates)
         )
-        # print(expr.compile(compile_kwargs={"literal_binds": True}))
         return await self.database.execute(expr)
 
     async def delete(self, each: bool = False, **kwargs: Any) -> int:
         if kwargs:
             return await self.filter(**kwargs).delete()
         if not each and not self.filter_clauses:
-            raise QueryDefinitionError('You cannot delete without filtering the queryset first. '
+            raise QueryDefinitionError(
-                                       'If you want to delete all rows use delete(each=True)')
+                "You cannot delete without filtering the queryset first. "
+                "If you want to delete all rows use delete(each=True)"
+            )
         expr = FilterQuery(filter_clauses=self.filter_clauses).apply(
             self.table.delete()
         )