Hi All, I'm really new to python and databases period, so please take it easy on me, im trying to learn. im trying to roll my own energy monitor and i cant really figure out how to get the number of entities in my data store.
class PowerData(db.Model): date = db.DateTimeProperty(auto_now_add=True) # timestamp kw = db.FloatProperty() # current kilowatt data (0.01 scale) my database will have more than 1000 entires in it quickly. i want to grab 1000 data points and send it to the google annotated timeline display, but i know my query will be limited to 1000 results. I want to write a query that will return the number of entities in my datastore, then write a function that decimates (get every Nth one) the data based on a hop factor that will give me less than 100 data points. 1- i have no idea how to get the full size of the datastore if its greater than 1000 entities 2- i dont know how to grab the decimated data in a way that wont be computationaly expensive im not looking for handout code, just throw me a bone for something to read up on? is this a decent way to structure the data base? should i change it before i got further? thanks, adam --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
