Hi Oliver. This page may help explain the difference between these fields: http://code.google.com/appengine/docs/python/datastore/keysandentitygroups.html
When you create entities, you have the option of specifying a unique key name that you can use to reference these entities directly (e.g. retrieving entities without queries, thereby improving the performance of your application). If you don't pass in a key name, a unique ID will be created for you, which is contained in the ID field. The key field is a Base64 encoding of the full key, including application ID and path. This is what is stored when you use reference properties for example. - Jason On Mon, May 11, 2009 at 4:52 PM, Oliver Zheng <[email protected]>wrote: > > I have been looking at the stored data of some apps, and noticed those > 3 columns. Key appears to be a hash/string of some sort. ID is usually > empty. Key name looks like an actual readable identifier, but it's > usually just "key_" + username or something that already exists. > > What is the use for any of this, from the perspective of a (python) > app? Why are they created and what can or should I do with them? > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
