生成唯一编号序列，以用作app引擎数据存储的实体密钥

Question

Has anyone got any example code for creating a unique number sequence to be used as keys for an entity in a Google app engine datastore?

Would like to use sequential order numbers as the key.

Answer 1

Use db.allocate_ids() as described here to generate unique IDs for your entities.

Here's a quick example derived from the example at the above link:

from google.appengine.ext import db

# get unique ID number - I just get 1 here, but you could get many ...
new_ids = db.allocate_ids(handmade_key, 1)

# db.allocate_ids() may return longs but db.Key.from_path requires an int (issue 2970)
new_id_num = int(new_id[0])

# assign the new ID to an entity
new_key = db.Key.from_path('MyModel', new_id_num)
new_instance = MyModel(key=new_key)
...
new_instance.put()

( issue 2970 reference )

Answer 2

您可能想看看如何在Google AppEngine上实现“自动增量” ，您可以在其中找到序列号的实现。