将neo4j的一个节点上的关系移动到另一个节点上

将neo4j中一个节点的全部关系移动到另一个节点上面，采用先建立新关系，之后删除原先的关系的方式

 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