Question

I have db model, where one property has auto_now_add=True. But looks like it doesn’t work as I’ve expected – it is updated each time when put is called (I use my own key_name, so second/third/N call of put doesn’t really create new record – just update it).

Here is the code:

class User(db.Model):
    id = db.IntegerProperty()
    added = db.DateTimeProperty(auto_now_add=True)
    name = db.StringProperty()

...
    # this handler can be called several times
    def get(self):
        user = User(key_name="id"+unique_user_id)
        user.id = unique_user_id
        user.name = current_name
        user.put()

Answer 1

You are recreating the entity each time, here is how the code should look like:

#This will create the object only once
return User.get_or_insert(key_name="id%d" % unique_user_id, 
                          id=unique_user_id, 
                          name = current_name)

#This will create the object and update some properties
#You can't change the value of key_name
user = User.get_or_insert(key_name="id%d" % unique_user_id, 
                          id=unique_user_id)
user.name = name
user.put()
return user