update docs, cleaning

docs_src/queries/docs003.py

@@ -0,0 +1,32 @@
+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: int = ormar.Integer(primary_key=True)
+    title: str = ormar.String(max_length=200)
+    author: str = ormar.String(max_length=100)
+    genre: str = 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')
+
+# if not exist the instance will be persisted in db
+vol2 = await Book.objects.update_or_create(title="Volume II", author='Anonymous', genre='Fiction')
+assert await Book.objects.count() == 1
+
+# if pk or pkname passed in kwargs (like id here) the object will be updated
+assert await Book.objects.update_or_create(id=vol2.id, genre='Historic')
+assert await Book.objects.count() == 1