def _transaction_id_subquery(self, obj, next_or_prev='next', alias=None):
if next_or_prev == 'next':
op = operator.gt
func = sa.func.min
else:
op = operator.lt
func = sa.func.max
if alias is None:
alias = sa.orm.aliased(obj)
table = alias.__table__
if hasattr(alias, 'c'):
attrs = alias.c
else:
attrs = alias
else:
table = alias.original
attrs = alias.c
query = (sa.select(
[func(getattr(attrs, tx_column_name(obj)))],
from_obj=[table]).where(
sa.and_(
op(getattr(attrs, tx_column_name(obj)),
getattr(obj, tx_column_name(obj))), *[
getattr(attrs, pk) == getattr(obj, pk)
for pk in get_primary_keys(obj.__class__)
if pk != tx_column_name(obj)
])).correlate(table))
return query
def parent_identity(obj_or_class):
if (
isinstance(obj_or_class, sa.sql.selectable.Alias) or
isinstance(obj_or_class, sa.Table)
):
return tuple(
column
for column in obj_or_class.c
if column.name != 'transaction_id'
and column.primary_key
)
return tuple(
getattr(obj_or_class, column_key)
for column_key in get_primary_keys(obj_or_class).keys()
if column_key != tx_column_name(obj_or_class)
)
def update_version_validity(self, parent, version_obj):
"""
Updates previous version object end_transaction_id based on given
parent object and newly created version object.
This method is only used when using 'validity' versioning strategy.
:param parent: SQLAlchemy declarative parent object
:parem version_obj: SQLAlchemy declarative version object
.. seealso:: :func:`version_validity_subquery`
"""
session = sa.orm.object_session(version_obj)
for class_ in version_obj.__class__.__mro__:
if class_ in self.manager.parent_class_map:
subquery = self.version_validity_subquery(
parent,
version_obj,
alias=sa.orm.aliased(class_.__table__)
)
query = (
session.query(class_.__table__)
.filter(
sa.and_(
getattr(
class_,
tx_column_name(version_obj)
) == subquery,
*[
getattr(version_obj, pk) ==
getattr(class_.__table__.c, pk)
for pk in get_primary_keys(class_)
if pk != tx_column_name(class_)
]
)
)
)
query.update(
{
end_tx_column_name(version_obj):
self.current_transaction.id
},
synchronize_session=False
)
def update_version_validity(self, parent, version_obj):
"""
Updates previous version object end_transaction_id based on given
parent object and newly created version object.
This method is only used when using 'validity' versioning strategy.
:param parent: SQLAlchemy declarative parent object
:parem version_obj: SQLAlchemy declarative version object
.. seealso:: :func:`version_validity_subquery`
"""
session = sa.orm.object_session(version_obj)
for class_ in version_obj.__class__.__mro__:
if class_ in self.manager.parent_class_map:
subquery = self.version_validity_subquery(
parent,
version_obj,
alias=sa.orm.aliased(class_.__table__)
)
query = (
session.query(class_.__table__)
.filter(
sa.and_(
getattr(
class_,
tx_column_name(version_obj)
) == subquery,
*[
getattr(version_obj, pk) ==
getattr(class_.__table__.c, pk)
for pk in get_primary_keys(class_)
if pk != tx_column_name(class_)
]
)
)
)
query.update(
{
end_tx_column_name(version_obj):
self.current_transaction.id
},
synchronize_session=False
)
def _transaction_id_subquery(self, obj, next_or_prev='next', alias=None):
if next_or_prev == 'next':
op = operator.gt
func = sa.func.min
else:
op = operator.lt
func = sa.func.max
if alias is None:
alias = sa.orm.aliased(obj)
table = alias.__table__
if hasattr(alias, 'c'):
attrs = alias.c
else:
attrs = alias
else:
table = alias.original
attrs = alias.c
query = (
sa.select(
[func(
getattr(attrs, tx_column_name(obj))
)],
from_obj=[table]
)
.where(
sa.and_(
op(
getattr(attrs, tx_column_name(obj)),
getattr(obj, tx_column_name(obj))
),
*[
getattr(attrs, pk) == getattr(obj, pk)
for pk in get_primary_keys(obj.__class__)
if pk != tx_column_name(obj)
]
)
)
.correlate(table)
)
return query
def test_table(self, Building):
assert get_primary_keys(Building.__table__) == OrderedDict({
'_id': Building.__table__.c._id
})
def test_table_alias(self):
alias = sa.orm.aliased(self.Building.__table__)
assert get_primary_keys(alias) == OrderedDict({
'_id': alias.c._id
})
def test_class_alias(self):
alias = sa.orm.aliased(self.Building)
assert get_primary_keys(alias) == OrderedDict({
'id': self.Building.__table__.c._id
})
def test_declarative_object(self):
assert get_primary_keys(self.Building()) == OrderedDict({
'id': self.Building.__table__.c._id
})
def test_declarative_class(self):
assert get_primary_keys(self.Building) == OrderedDict({
'id': self.Building.__table__.c._id
})
def test_table(self):
assert get_primary_keys(self.Building.__table__) == OrderedDict({
'_id': self.Building.__table__.c._id
})
def test_declarative_class(self, Building):
assert get_primary_keys(Building) == OrderedDict(
{'id': Building.__table__.c._id})
def parent_identity(obj_or_class):
return tuple(
getattr(obj_or_class, column_key)
for column_key in get_primary_keys(obj_or_class).keys()
if column_key != tx_column_name(obj_or_class)
)
def test_class_alias(self, Building):
alias = sa.orm.aliased(Building)
assert get_primary_keys(alias) == OrderedDict(
{'id': Building.__table__.c._id})
def test_declarative_object(self, Building):
assert get_primary_keys(Building()) == OrderedDict({
'id': Building.__table__.c._id
})
def test_table_alias(self, Building):
alias = sa.orm.aliased(Building.__table__)
assert get_primary_keys(alias) == OrderedDict({
'_id': alias.c._id
})
def parent_identity(obj_or_class):
return tuple(
getattr(obj_or_class, column_key)
for column_key in get_primary_keys(obj_or_class).keys()
if column_key != tx_column_name(obj_or_class))
