from typing import List, Optional import ormar import pytest import pytest_asyncio from tests.lifespan import init_tests from tests.settings import create_config base_ormar_config = create_config() class Author(ormar.Model): ormar_config = base_ormar_config.copy(tablename="authors") id: int = ormar.Integer(primary_key=True) first_name: str = ormar.String(max_length=80) last_name: str = ormar.String(max_length=80) class Category(ormar.Model): ormar_config = base_ormar_config.copy(tablename="categories") id: int = ormar.Integer(primary_key=True) name: str = ormar.String(max_length=40) class Post(ormar.Model): ormar_config = base_ormar_config.copy(tablename="posts") id: int = ormar.Integer(primary_key=True) title: str = ormar.String(max_length=200) categories: Optional[List[Category]] = ormar.ManyToMany(Category) author: Optional[Author] = ormar.ForeignKey(Author, related_name="author_posts") create_test_database = init_tests(base_ormar_config) @pytest_asyncio.fixture(scope="function") async def cleanup(): yield async with base_ormar_config.database: PostCategory = Post.ormar_config.model_fields["categories"].through await PostCategory.objects.delete(each=True) await Post.objects.delete(each=True) await Category.objects.delete(each=True) await Author.objects.delete(each=True) @pytest.mark.asyncio async def test_selecting_related(cleanup): async with base_ormar_config.database: guido = await Author.objects.create(first_name="Guido", last_name="Van Rossum") post = await Post.objects.create(title="Hello, M2M", author=guido) news = await Category.objects.create(name="News") recent = await Category.objects.create(name="Recent") await post.categories.add(news) await post.categories.add(recent) assert len(await post.categories.all()) == 2 # Loads categories and posts (2 queries) and perform the join in Python. categories = await Category.objects.select_related(Category.posts).all() assert len(categories) == 2 assert categories[0].name == "News" news_posts = await news.posts.select_related(Post.author).all() assert news_posts[0].author == guido assert (await post.categories.limit(1).all())[0] == news assert (await post.categories.offset(1).limit(1).all())[0] == recent assert await post.categories.first() == news assert await post.categories.exists() author = await Author.objects.prefetch_related( Author.author_posts.categories ).get() assert len(author.author_posts) == 1 assert author.author_posts[0].title == "Hello, M2M" assert author.author_posts[0].categories[0].name == "News" assert author.author_posts[0].categories[1].name == "Recent" post = await Post.objects.select_related([Post.author, Post.categories]).get() assert len(post.categories) == 2 assert post.categories[0].name == "News" assert post.categories[1].name == "Recent" assert post.author.first_name == "Guido"