读代码遇到一些疑问，求解

2011-08-17 14:33:05 +08:00

linsk

https://github.com/livid/v2ex/blob/master/topic.py#L1118

＃1130～1134行
q = db.GqlQuery("SELECT * FROM Reply WHERE num = :1", int(reply_num))
if q[0]:
reply = q[0]
topic = reply.topic
node = topic.node

＃问1134行为什么不需要先在数据库中获得？因为整个topic对象都存储在reply.topic中吗？

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所在节点

Project Babel

2 条回复

Weakdancer

2011-08-17 14:58:28 +08:00

https://github.com/livid/v2ex/blob/master/v2ex/babel/__init__.py#L175

Livid 用了Google提供的 ReferenceProperty

http://code.google.com/intl/zh-CN/appengine/docs/python/datastore/typesandpropertyclasses.html#ReferenceProperty

linsk

2011-08-17 15:01:01 +08:00

@Weakdancer 感谢你花费的5分钟，很大帮助