def move_relations(source_node_id,target_node_id,graph=None):

     """

     将 source_node_id 上所有的关系移动到 target_node_id 上

     """

     if source_node_id is None or target_node_id is None:

         return

     if graph is None:

         graph = get_graph()

     r_ids = []

     match = "match (x)-[r]-(n) where id(x)=%s return r" % (source_node_id)

     data = graph.run(match).data()

     for d in data:

         for tk,tv in d.items():

             relations = tv.relationships

             for r in relations:

                 if r.identity in r_ids:

                     continue

                 r_ids.append(r.identity)

                 from_id = 0

                 to_id = 0

                 if r.start_node.identity == source_node_id:

                     from_id = target_node_id

                     to_id = r.end_node.identity

                 else:

                     from_id = r.start_node.identity

                     to_id = target_node_id

                 labels = ""

                 if r.types() is not None:

                     for la in r.types():

                         labels+=":" + la

                 fields = []

                 fields_str = ""

                 for k,v in r.items():

                     fields.append("%s:'%s'" % (k,v))

                 if len(fields) > 0:

                     fields_str = ",".join(fields)

                     fields_str = "{%s}" % fields_str

                 match = "match (x),(y) where id(x)=%s and id(y)=%s create (x)-[r%s%s]->(y) return id(r)" % (from_id,to_id,labels,fields_str)

                 result=graph.run(match).data()

                 if result is None or len(result)==0:

                     return False

                 match = "match ()-[r]-() where id(r)=%s delete r" % (r.identity)

                 graph.run(match)

                 return True

     return