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 _entity_by_id_builder(self, entity, id_val, add_labels=False):
qv = entity.query_variable
if not qv:
qv = VM.set_query_var(entity)
_id = VM.get_next(entity, 'id')
_id = Param(_id, id_val)
node_kwargs = {}
if add_labels:
node_kwargs['labels'] = entity.labels
if isinstance(entity, Relationship):
node = __.node(**node_kwargs).relationship(qv).node()
else:
node = __.node(qv, **node_kwargs)
where = __.ID(qv) == _id
self.matches.append(node)
self.wheres.append(where)
self.returns.append(entity.query_variable)
return self
def _node_by_id(self, entity):
qv = entity.query_variable
if not qv:
qv = VM.set_query_var(entity)
_id = VM.get_next(entity, 'id')
_id = Param(_id, entity.id)
return __.node(qv).WHERE(__.ID(qv) == _id)
def delete_node(self, entity):
_id = VM.get_next(entity, 'id')
_id = Param(_id, entity.id)
match = __.node(entity.query_variable)
match.WHERE(__.ID(entity.query_variable) == _id)
self.matches.append(match)
self.deletes.append(entity.query_variable)
return self
def delete_relationship(self, entity):
_id = VM.get_next(entity, 'id')
_id = Param(_id, entity.id)
match = __.node()
match.rel(entity.query_variable, labels=entity.labels)
match.node()
match.WHERE(__.ID(entity.query_variable) == _id)
self.matches.append(match)
self.deletes.append(entity.query_variable)
return self
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
def _build_start(self):
pypher = Pypher()
if self.start_entity.id:
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 test_will_allow_binding_of_pypher_instances_as_values(self):
p = Pypher()
p.bind_param(__.ID('x'), 'SOME_ID')
str(p)
params = p.bound_params
self.assertIn('SOME_ID', params)
self.assertEqual('id(x)', params['SOME_ID'])
self.assertEqual(1, len(params))
# do it in a Pypher string
p = Pypher()
val = 'some value {}'.format(random())
name = 'name'
p.MATCH.node('p', 'person', lastname=__.coalesce(name, val))
cy = str(p)
params = p.bound_params
name = get_dict_key(params, 'name')
val = get_dict_key(params, val)
exp = 'MATCH (p:`person` {{`lastname`: coalesce(${name}, ${val})}})'.format(
name=name, val=val)
self.assertEqual(3, len(params))
self.assertEqual(exp, cy)
# manually use Param and pass it in
p = Pypher()
val = 'some value {}'.format(random())
name = 'name'
ln = Param(name, __.coalesce(name, val))
p.MATCH.node('p', 'person', lastname=ln)
cy = str(p)
params = p.bound_params
name = get_dict_key(params, 'name')
val = get_dict_key(params, val)
exp = 'MATCH (p:`person` {{`lastname`: coalesce(${name}, ${val})}})'.format(
name=name, val=val)
self.assertEqual(3, len(params))
self.assertEqual(exp, cy)
def get_by_ids(self, entity, ids):
p = Pypher()
p.MATCH
if isinstance(entity, Relationship):
var = 'rel'
p.node().rel(var, labels=entity.labels).node()
else:
var = 'node'
p.node(var, labels=entity.labels)
id_params = []
for i in ids:
key = 'entity_id_{}'.format(i)
id_params.append(Param(key, i))
p.WHERE.COR(__.ID(var).IN(*id_params))
p.RETURN(var)
return str(p), p.bound_params
def entity_where(entity):
if entity.id:
wheres.append(__.ID(entity.query_variable) == entity.id)
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
