Add chained_join relationship helper
This commit is contained in:
Konsta Vesterinen
@@ -375,6 +375,8 @@ except ImportError:
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# SQLAlchemy 0.8
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from sqlalchemy.sql.expression import _FunctionGenerator
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from .relationships import chained_join
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aggregated_attrs = WeakKeyDictionary(defaultdict(list))
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@@ -452,6 +454,26 @@ def get_aggregate_query(agg_expr, relationships):
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return query.where(condition)
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def local_condition(prop, objects):
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pairs = prop.local_remote_pairs
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if prop.secondary is not None:
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column = pairs[1][0]
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key = pairs[1][0].key
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else:
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column = pairs[0][0]
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key = pairs[0][1].key
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values = []
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for obj in objects:
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try:
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values.append(getattr(obj, key))
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except sa.orm.exc.ObjectDeletedError:
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pass
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if values:
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return column.in_(values)
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class AggregatedValue(object):
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def __init__(self, class_, attr, relationships, expr):
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self.class_ = class_
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@@ -480,7 +502,7 @@ class AggregatedValue(object):
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)
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if len(self.relationships) == 1:
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prop = self.relationships[-1].property
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condition = self.local_condition(prop, objects)
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condition = local_condition(prop, objects)
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if condition is not None:
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return query.where(condition)
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else:
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@@ -498,7 +520,7 @@ class AggregatedValue(object):
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remote_pairs = property_.local_remote_pairs
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local = remote_pairs[0][0]
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remote = remote_pairs[0][1]
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condition = self.local_condition(
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condition = local_condition(
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self.relationships[0].property,
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objects
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)
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@@ -507,55 +529,15 @@ class AggregatedValue(object):
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local.in_(
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sa.select(
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[remote],
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from_obj=[self.multi_level_aggregate_query_base]
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from_obj=[
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chained_join(*reversed(self.relationships))
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]
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).where(
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condition
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)
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)
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)
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@property
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def multi_level_aggregate_query_base(self):
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property_ = self.relationships[-1].property
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from_ = property_.mapper.class_.__table__
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for relationship in reversed(self.relationships[0:-1]):
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property_ = relationship.property
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if property_.secondary is not None:
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from_ = from_.join(
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property_.secondary,
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property_.primaryjoin
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)
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from_ = from_.join(
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property_.mapper.class_,
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property_.secondaryjoin
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)
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else:
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from_ = from_.join(
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property_.mapper.class_,
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property_.primaryjoin
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)
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return from_
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def local_condition(self, prop, objects):
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pairs = prop.local_remote_pairs
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if prop.secondary is not None:
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column = pairs[1][0]
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key = pairs[1][0].key
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else:
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column = pairs[0][0]
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key = pairs[0][1].key
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values = []
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for obj in objects:
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try:
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values.append(getattr(obj, key))
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except sa.orm.exc.ObjectDeletedError:
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pass
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if values:
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return column.in_(values)
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class AggregationManager(object):
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def __init__(self):
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1
sqlalchemy_utils/relationships/__init__.py
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1
sqlalchemy_utils/relationships/__init__.py
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@@ -0,0 +1 @@
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from .chained_join import chained_join
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28
sqlalchemy_utils/relationships/chained_join.py
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28
sqlalchemy_utils/relationships/chained_join.py
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@@ -0,0 +1,28 @@
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def chained_join(*relationships):
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property_ = relationships[0].property
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if property_.secondary is not None:
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from_ = property_.secondary.join(
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property_.mapper.class_.__table__,
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property_.secondaryjoin
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)
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else:
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from_ = property_.mapper.class_.__table__
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for relationship in relationships[1:]:
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prop = relationship.property
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if prop.secondary is not None:
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from_ = from_.join(
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prop.secondary,
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prop.primaryjoin
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)
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from_ = from_.join(
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prop.mapper.class_,
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prop.secondaryjoin
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)
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else:
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from_ = from_.join(
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prop.mapper.class_,
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prop.primaryjoin
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)
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return from_
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0
tests/relationships/__init__.py
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0
tests/relationships/__init__.py
Normal file
266
tests/relationships/test_chained_join.py
Normal file
266
tests/relationships/test_chained_join.py
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@@ -0,0 +1,266 @@
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import sqlalchemy as sa
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from sqlalchemy_utils.relationships import chained_join
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from tests import TestCase
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class TestChainedJoinForManyToManyToManyToMany(TestCase):
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dns = 'postgres://postgres@localhost/sqlalchemy_utils_test'
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create_tables = False
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def create_models(self):
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catalog_category = sa.Table(
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'catalog_category',
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self.Base.metadata,
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sa.Column('catalog_id', sa.Integer, sa.ForeignKey('catalog.id')),
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sa.Column('category_id', sa.Integer, sa.ForeignKey('category.id'))
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)
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category_subcategory = sa.Table(
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'category_subcategory',
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self.Base.metadata,
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sa.Column(
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'category_id',
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sa.Integer,
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sa.ForeignKey('category.id')
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),
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sa.Column(
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'subcategory_id',
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sa.Integer,
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sa.ForeignKey('sub_category.id')
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)
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)
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subcategory_product = sa.Table(
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'subcategory_product',
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self.Base.metadata,
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sa.Column(
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'subcategory_id',
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sa.Integer,
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sa.ForeignKey('sub_category.id')
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),
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sa.Column(
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'product_id',
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sa.Integer,
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sa.ForeignKey('product.id')
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)
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)
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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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categories = sa.orm.relationship(
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'Category',
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backref='catalogs',
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secondary=catalog_category
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)
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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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sub_categories = sa.orm.relationship(
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'SubCategory',
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backref='categories',
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secondary=category_subcategory
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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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products = sa.orm.relationship(
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'Product',
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backref='sub_categories',
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secondary=subcategory_product
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)
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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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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 test_simple_join(self):
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assert str(chained_join(self.Catalog.categories)) == (
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'catalog_category JOIN category ON '
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'category.id = catalog_category.category_id'
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)
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def test_two_relations(self):
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sql = chained_join(
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self.Catalog.categories,
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self.Category.sub_categories
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)
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assert str(sql) == (
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'catalog_category JOIN category ON category.id = '
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'catalog_category.category_id JOIN category_subcategory ON '
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'category.id = category_subcategory.category_id JOIN sub_category '
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'ON sub_category.id = category_subcategory.subcategory_id'
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)
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def test_three_relations(self):
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sql = chained_join(
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self.Catalog.categories,
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self.Category.sub_categories,
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self.SubCategory.products
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)
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assert str(sql) == (
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'catalog_category JOIN category ON category.id = '
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'catalog_category.category_id JOIN category_subcategory ON '
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'category.id = category_subcategory.category_id JOIN sub_category '
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'ON sub_category.id = category_subcategory.subcategory_id JOIN '
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'subcategory_product ON sub_category.id = '
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'subcategory_product.subcategory_id JOIN product ON product.id = '
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'subcategory_product.product_id'
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)
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class TestChainedJoinFor3LevelDeepOneToMany(TestCase):
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dns = 'postgres://postgres@localhost/sqlalchemy_utils_test'
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create_tables = False
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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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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_categories = sa.orm.relationship(
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'SubCategory', 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(
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'Product',
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backref='sub_category'
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)
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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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def __repr__(self):
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return '<Product id=%r>' % self.id
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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 test_simple_join(self):
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assert str(chained_join(self.Catalog.categories)) == 'category'
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def test_two_relations(self):
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sql = chained_join(
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self.Catalog.categories,
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self.Category.sub_categories
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)
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assert str(sql) == (
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'category JOIN sub_category ON category.id = '
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'sub_category.category_id'
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)
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def test_three_relations(self):
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sql = chained_join(
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self.Catalog.categories,
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self.Category.sub_categories,
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self.SubCategory.products
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)
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assert str(sql) == (
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'category JOIN sub_category ON category.id = '
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'sub_category.category_id JOIN product ON sub_category.id = '
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'product.sub_category_id'
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)
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class TestChainedJoinForOneToOneToOneToOne(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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category = sa.orm.relationship(
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'Category',
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uselist=False,
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backref='catalog'
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)
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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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product = sa.orm.relationship(
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'Product',
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uselist=False,
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backref='sub_category'
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)
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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.Integer)
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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 test_simple_join(self):
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assert str(chained_join(self.Catalog.category)) == 'category'
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def test_two_relations(self):
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sql = chained_join(
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self.Catalog.category,
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self.Category.sub_category
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)
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assert str(sql) == (
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'category JOIN sub_category ON category.id = '
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'sub_category.category_id'
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)
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def test_three_relations(self):
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sql = chained_join(
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self.Catalog.category,
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self.Category.sub_category,
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self.SubCategory.product
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)
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assert str(sql) == (
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'category JOIN sub_category ON category.id = '
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'sub_category.category_id JOIN product ON sub_category.id = '
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'product.sub_category_id'
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)
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