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