97 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			97 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
import sqlalchemy as sa
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from sqlalchemy_utils.observer import observes
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from tests import TestCase
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class TestObservesForOneToManyToOneToMany(TestCase):
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    dns = 'postgres://postgres@localhost/sqlalchemy_utils_test'
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    def create_models(self):
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        class Catalog(self.Base):
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            __tablename__ = 'catalog'
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            id = sa.Column(sa.Integer, primary_key=True)
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            product_count = sa.Column(sa.Integer, default=0)
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            @observes('categories.sub_category.products')
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            def product_observer(self, products):
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                self.product_count = len(products)
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            categories = sa.orm.relationship('Category', backref='catalog')
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        class Category(self.Base):
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            __tablename__ = 'category'
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            id = sa.Column(sa.Integer, primary_key=True)
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            catalog_id = sa.Column(sa.Integer, sa.ForeignKey('catalog.id'))
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            sub_category = sa.orm.relationship(
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                'SubCategory',
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                uselist=False,
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                backref='category'
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            )
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        class SubCategory(self.Base):
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            __tablename__ = 'sub_category'
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            id = sa.Column(sa.Integer, primary_key=True)
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            category_id = sa.Column(sa.Integer, sa.ForeignKey('category.id'))
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            products = sa.orm.relationship('Product', backref='sub_category')
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        class Product(self.Base):
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            __tablename__ = 'product'
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            id = sa.Column(sa.Integer, primary_key=True)
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            price = sa.Column(sa.Numeric)
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            sub_category_id = sa.Column(
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                sa.Integer, sa.ForeignKey('sub_category.id')
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            )
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        self.Catalog = Catalog
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        self.Category = Category
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        self.SubCategory = SubCategory
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        self.Product = Product
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    def create_catalog(self):
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        sub_category = self.SubCategory(products=[self.Product()])
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        category = self.Category(sub_category=sub_category)
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        catalog = self.Catalog(categories=[category])
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        self.session.add(catalog)
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        self.session.flush()
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        return catalog
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    def test_simple_insert(self):
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        catalog = self.create_catalog()
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        assert catalog.product_count == 1
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    def test_add_leaf_object(self):
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        catalog = self.create_catalog()
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        product = self.Product()
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        catalog.categories[0].sub_category.products.append(product)
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        self.session.flush()
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        assert catalog.product_count == 2
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    def test_remove_leaf_object(self):
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        catalog = self.create_catalog()
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        product = self.Product()
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        catalog.categories[0].sub_category.products.append(product)
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        self.session.flush()
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        self.session.delete(product)
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        self.session.flush()
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        assert catalog.product_count == 1
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    def test_delete_intermediate_object(self):
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        catalog = self.create_catalog()
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        self.session.delete(catalog.categories[0].sub_category)
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        self.session.commit()
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        assert catalog.product_count == 0
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    def test_gathered_objects_are_distinct(self):
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        catalog = self.Catalog()
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        category = self.Category(catalog=catalog)
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        product = self.Product()
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        category.sub_category = self.SubCategory(products=[product])
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        self.session.add(
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            self.Category(catalog=catalog, sub_category=category.sub_category)
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        )
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        self.session.commit()
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        assert catalog.product_count == 1
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