def test_can_append_two_instances_first_is_empty(self):
p = Pypher()
p2 = Pypher()
p2.two
p.append(p2)
exp = 'two'
exp2 = 'two'
s = str(p)
s2 = str(p2)
self.assertEqual(exp, s)
self.assertEqual(exp2, s2)
def test_can_append_two_instances(self):
p = Pypher()
p2 = Pypher()
p.one
p2.two
p.append(p2)
exp = 'one two'
exp2 = 'two'
s = str(p)
s2 = str(p2)
self.assertEqual(exp, s)
self.assertEqual(exp2, s2)
class RelatedEntityQuery(_BaseQuery):
def __init__(self,
direction='out',
relationship_entity=None,
relationship_type=None,
relationship_properties=None,
start_entity=None,
end_entity=None,
params=None,
single_relationship=False,
start_query_variable='start_node',
relationship_query_variable='relt',
end_query_variable='end_node'):
super(RelatedEntityQuery, self).__init__()
self.direction = direction
self.relationship_entity = relationship_entity
self.relationship_type = relationship_type
self.start_query_variable = start_query_variable
self.relationship_query_variable = relationship_query_variable
self.end_query_variable = end_query_variable
self._start_entity = None
self.start_entity = start_entity
self._end_entity = None
self.end_entity = end_entity
self.relationship_properties = relationship_properties or {}
self.params = params
self.skip = None
self.limit = 1 if single_relationship else None
def reset(self):
super(RelatedEntityQuery, self).reset()
self.skip = None
self.limit = None
if self.start_entity:
self.start_entity.query_variable = self.start_query_variable
VM.set_query_var(self.start_entity)
if self.end_entity:
self.end_entity.query_variable = self.end_query_variable
VM.set_query_var(self.end_entity)
def _get_relationship_entity(self):
return self._relationship_entity
def _set_relationship_entity(self, relationship):
if relationship is not None and not isinstance(relationship,
Relationship):
raise AttributeError('Must be an <Relationship> and not'
' a <{t}>'.format(t=type(relationship)))
self._relationship_entity = relationship
return self
relationship_entity = property(_get_relationship_entity,
_set_relationship_entity)
def _get_start_entity(self):
return self._start_entity
def _set_start_entity(self, entity):
if entity is not None and not isinstance(entity, Node):
raise AttributeError('entity must be a Node instance')
if entity:
entity.query_variable = self.start_query_variable
VM.set_query_var(entity)
self._start_entity = entity
start_entity = property(_get_start_entity, _set_start_entity)
def _get_end_entity(self):
return self._end_entity
def _set_end_entity(self, entity):
if entity is not None and not isinstance(entity, Node):
raise AttributeError('entity must be a Node instance')
if entity:
entity.query_variable = self.end_query_variable
VM.set_query_var(entity)
self._end_entity = entity
end_entity = property(_get_end_entity, _set_end_entity)
def _build_start(self):
pypher = Pypher()
if self.start_entity.id is not None:
qv = self.start_entity.query_variable
where = __.ID(qv) == self.start_entity.id
pypher.NODE(qv)
self.wheres.append(where)
else:
pypher.NODE(self.start_query_variable,
labels=self.start_entity.labels)
return pypher
def _build_end(self):
pypher = Pypher()
qv = self.end_query_variable
labels = None
if self.end_entity:
qv = self.end_entity.query_variable
labels = self.end_entity.labels
pypher.NODE(qv, labels=labels)
self.returns.append(qv)
return pypher
def _build_relationship(self):
pypher = Pypher()
if self.relationship_entity:
self.relationship_entity.query_variable =\
self.relationship_query_variable
VM.set_query_var(self.relationship_entity)
pypher.relationship(self.relationship_entity.query_variable,
direction=self.direction,
labels=self.relationship_entity.labels,
**self.relationship_properties)
else:
pypher.relationship(direction=self.direction,
labels=self.relationship_type)
return pypher
def query(self, return_relationship=False, returns=None):
if not self.start_entity:
raise RelatedQueryException(('Related objects must have a'
' start entity'))
self.pypher = Pypher()
pypher = self.pypher
self.matches.insert(0, self._build_end())
self.matches.insert(0, self._build_relationship())
self.matches.insert(0, self._build_start())
self.pypher.MATCH
for match in self.matches:
self.pypher.append(match)
if self.wheres:
self.pypher.WHERE.CAND(*self.wheres)
if return_relationship:
ret = getattr(__, self.relationship_query_variable)
self.returns = [
ret,
]
returns = returns or self.returns
self.pypher.RETURN(*returns)
if self.orders:
self.pypher.ORDER.BY(*self.orders)
if self.skip is not None:
self.pypher.SKIP(self.skip)
if self.limit is not None:
self.pypher.LIMIT(self.limit)
self.reset()
return str(pypher), pypher.bound_params
def connect(self, entity, properties=None):
if not self.start_entity:
message = ('The relationship {} does not have a start'
' entity'.format(self.relationship_entity
or self.relationship_type))
raise RelatedQueryException(('The relationship {} does not '))
if self.start_entity == entity:
msg = ('the start entity {} cannot be the same as the'
' end entity'.format(entity))
raise RelatedQueryException(msg)
start = self.start_entity
end = entity
if self.direction == 'in':
start, end = end, start
kwargs = {
'start': start,
'end': end,
'properties': properties,
}
if self.relationship_entity:
return self.relationship_entity.__class__(**kwargs)
kwargs['labels'] = self.relationship_type
return Relationship(**kwargs)
def delete(self, entity):
if isinstance(entity, Relationship):
if entity.id is not None:
query = Query(entity)
return query.delete()
elif entity.end and hasattr(entity.end, 'id'):
self.matches.insert(0, self._build_end())
self.matches.insert(0, self._build_relationship())
self.matches.insert(0, self._build_start())
self.pypher.MATCH
for match in self.matches:
self.pypher.append(match)
self.pypher.DETACH.DELETE(self.relationship_query_variable)
self.reset()
return str(self.pypher), self.pypher.bound_params
def delete_by_entity_id(self, *ids):
if not ids:
msg = 'There must be ids passed in to the delete method'
raise AttributeError(msg)
def _build_start():
pypher = Pypher()
if self.start_entity.id is not None:
qv = self.start_entity.query_variable
where = __.ID(qv) == self.start_entity.id
pypher.NODE(qv)
self.wheres.append(where)
else:
pypher.NODE(self.start_query_variable)
return pypher
self.pypher = Pypher()
self.matches.insert(0, self._build_end())
self.matches.insert(0, self._build_relationship())
self.matches.insert(0, _build_start())
self.pypher.MATCH
for match in self.matches:
self.pypher.append(match)
id_params = []
for i in ids:
key = 'end_id_{}'.format(i)
id_params.append(Param(key, i))
self.wheres.append(__.ID(self.end_query_variable).IN(*id_params))
_id = __.ID(self.start_query_variable)
if self.start_entity.id is not None:
self.wheres.append(_id == self.start_entity.id)
# else:
# wheres.append(_id)
self.pypher.WHERE.CAND(*self.wheres)
self.pypher.DELETE(self.relationship_query_variable)
self.reset()
return str(self.pypher), self.pypher.bound_params
def save_relationship(self, entity, ensure_unique=False):
"""this method handles creating and saving relationships.
It will hanle quite a few situations.
Given the structure:
(start)-[rel]->[end]
We can have:
* A new start node
* An existing start node
* A new rel
* An existing rel
* A new end node
* An existing end node
Each start, rel, and end could have uniqueness assigned to it
* start/end could have unique properties
* rel could have unique relationships
A Chyper query should be generated that looks something like this,
depending on the settings for each of the nodes:
MERGE (n_0:Node {`key`: val})
ON CREATE SET n_0.key = val, n_0.key2 = val2
ON MATCH SET n_0.key = val, n_0.key2 = val2
CREATE (n_0)-[r_0:RelLabel, {`key`: someVal}]->(n_1:Node {`key`: val})
RETURN n_0, n_1, r_0
"""
start = entity.start
start_properties = {}
end = entity.end
end_properties = {}
props = self._properties(entity)
if start is None or end is None:
raise Exception('The relationship must have a start and end node')
if not isinstance(start, Node):
start = Node(id=start)
if not isinstance(end, Node):
end = Node(id=end)
VM.set_query_var(start)
VM.set_query_var(end)
VM.set_query_var(entity)
rel = Pypher()
if start not in self.matched_entities:
if start.id is not None:
self._update_properties(start)
self.matches.append(self._node_by_id(start))
else:
start_properties = self._properties(start)
self.matched_entities.append(start)
self.returns.append(start.query_variable)
if end not in self.matched_entities:
if end.id is not None:
self._update_properties(end)
self.matches.append(self._node_by_id(end))
else:
end_properties = self._properties(end)
self.matched_entities.append(end)
self.returns.append(end.query_variable)
if entity.id is None:
if start.id is not None:
rel = rel.node(start.query_variable)
else:
start_query = Query(start, self.params)
start_query.build_save_pypher()
if len(start_query.creates):
rel.append(*start_query.creates)
elif len(start_query.merges):
has_matches = len(self.matches) > 0
start_merge = Pypher()
start_merge.MERGE(*start_query.merges)
if start_query.on_create_sets:
start_merge.OnCreateSet(*start_query.on_create_sets)
if start_query.on_match_sets:
start_merge.OnMatchSet(*start_query.on_match_sets)
self.before_matches.append(start_merge)
rel.node(start.query_variable)
rel.rel(entity.query_variable,
labels=entity.labels,
direction='out',
**props)
if end.id is not None:
rel.node(end.query_variable)
else:
end_query = Query(end, self.params)
end_query.build_save_pypher()
if len(end_query.creates):
rel.append(*end_query.creates)
elif len(end_query.merges):
end_merge = Pypher().MERGE(*end_query.merges)
if end_query.on_create_sets:
end_merge.OnCreateSet(*end_query.on_create_sets)
if end_query.on_match_sets:
end_merge.OnMatchSet(*end_query.on_match_sets)
self.before_matches.append(end_merge)
rel.node(end.query_variable)
if ensure_unique:
self.merges.append(rel)
else:
self.creates.append(rel)
else:
_id = VM.get_next(entity, 'id')
_id = Param(_id, entity.id)
if start.id is not None:
rel = rel.node(start.query_variable)
else:
start_query = Query(start, self.params)
start_query.build_save_pypher()
if len(start_query.creates):
rel.append(*start_query.creates)
elif len(start_query.merges):
start_merge = Pypher().MERGE(*start_query.merges)
if start_query.on_create_sets:
start_merge.OnCreateSet(*start_query.on_create_sets)
if start_query.on_match_sets:
start_merge.OnMatchSet(*start_query.on_match_sets)
if len(self.matches):
self.matches[-1].append(start_merge)
else:
self.matches.append(start_merge)
rel.node(start.query_variable)
rel.rel(entity.query_variable,
labels=entity.labels,
direction='out')
if end.id is not None:
rel.node(end.query_variable)
else:
end_query = Query(end, self.params)
end_query.build_save_pypher()
if len(end_query.creates):
rel.append(*end_query.creates)
elif len(end_query.merges):
end_merge = Pypher().MERGE(*end_query.merges)
if end_query.on_create_sets:
end_merge.OnCreateSet(*end_query.on_create_sets)
if end_query.on_match_sets:
end_merge.OnMatchSet(*end_query.on_match_sets)
if len(self.matches):
self.matches[-1].append(end_merge)
else:
self.matches.append(end_merge)
rel.node(end.query_variable)
rel.WHERE(__.ID(entity.query_variable) == _id)
self._update_properties(entity)
self.matches.append(rel)
self.returns.append(entity.query_variable)
return self
