No, datastore can't do it. An entity is stored in the datastore as a key: value pair. Its value is combined by all its properties as a string.
It may looks like that: first: 'int|1|string|hello|email|he...@google.com' second: 'int|2|string|world|email|wo...@google.com' So you can only get/set all its properties at a same time. 2009/4/15 Andrew Fong <fongand...@gmail.com> > > Let's say I already know the key of an entity in the datastore I want > to update and want to update only a single property value inside that > entity. > > With SQL, you would simply do UPDATE table SET table.a = new_value > WHERE key=key_value > > Is it possible to do the same with the AppEngine datastore? If I > simply create a new db.Model instance with the same key and set the > new value, calling put on this instance overrides all properties for > this entity, not just the one I want to update. > > Therefore, I currently have to retrieve the existing entity, update > the value, and then do the put. This is two datastore operations > instead of just one. I'm doing a lot of batch operations using the > remote_api, and I'd like to minimize and round-trip times. > > -- Andrew > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
