Google App引擎-访问数据存储

Question

Hi i wonder if you could help provide some advice;

I have a python script allows users to post messages to the google app engine datastore - which uses ajax to post a message to the app engine. What i am trying to achieve is to have - in javascript- check the latest message being posted. I have looked at the GQL docs but cannot find out how to check for the latest post.

// if {{message.**LastPost**}} == "hello"
//do this....
//end if

Answer 1

The GQL query would simply be to order your data by the date ascending and then limit to 1.

Example:

SELECT * FROM messages ORDER BY date_submitted DESC LIMIT 1

See https://developers.google.com/appengine/docs/python/datastore/gqlreference for reference.

If all you want is the latest record of your messages object which contains the DB query you can simply use something like messages.get().message