>>> # get all posts written by a user
>>> u = User.query.get(1)
>>> u

>>> posts = u.posts.all()
>>> posts
[]

>>> # same, but with a user that has no posts
>>> u = User.query.get(2)
>>> u

>>> u.posts.all()
[]

>>> # print post author and body for all posts
>>> posts = Post.query.all()
>>> for p in posts:
...     print(p.id, p.author.username, p.body)
...
1 john my first post!

# get all users in reverse alphabetical order
>>> User.query.order_by(User.username.desc()).all()
[, ]