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ormar/tests/test_relations/test_python_style_relations.py

101 lines
3.3 KiB
Python

from typing import List, Optional
import databases
import pytest
import sqlalchemy
import ormar
from tests.settings import DATABASE_URL
database = databases.Database(DATABASE_URL, force_rollback=True)
metadata = sqlalchemy.MetaData()
class Author(ormar.Model):
class Meta:
tablename = "authors"
database = database
metadata = metadata
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):
class Meta:
tablename = "categories"
database = database
metadata = metadata
id: int = ormar.Integer(primary_key=True)
name: str = ormar.String(max_length=40)
class Post(ormar.Model):
class Meta:
tablename = "posts"
database = database
metadata = metadata
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")
@pytest.fixture(autouse=True, scope="module")
def create_test_database():
engine = sqlalchemy.create_engine(DATABASE_URL)
metadata.create_all(engine)
yield
metadata.drop_all(engine)
@pytest.fixture(scope="function")
async def cleanup():
yield
async with database:
PostCategory = Post.Meta.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 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"