Example from a livecoding stream, updated with fixes

rom_example_bruno.py

'''
This this was retyped from https://www.twitch.tv/videos/459202303 for notes and
then updated by the author of rom, me, Josiah Carlson


Notes:
* For created_at, or any default, if it is "callable", it will be called at
  entity creation/instantiation. In the demo in the video, we see:
    created_at = rom.DateTime(default=datetime.datetime.now())

  This should have been:
    created_at = rom.DateTime(default=datetime.datetime.now)

  ... Because otherwise, the now() is called on import, not on User() creation.
  Though arguably, it should have been
    created_at = rom.DateTime(default=datetime.datetime.utcnow)

  ... so we don't have to worry about timezones.

* The FULL_TEXT index keygen mangles tokens on their way through to the
  indexing step:

    In [2]: rom.FULL_TEXT('My Task #1')                                                                                     
    Out[2]: ['1', 'my', 'task']

  Those tokens are then indexed and searchable according to the `prefix` /
  `suffix` / `pattern` options provided.

  If you provided `prefix=True`, you can use:
    `Model.query.startswith(attr=...)`
    `Model.query.like(attr=...)`

  If you provided `suffix=True`, you can use:
    `Model.query.endswith(attr=...)`

  So in the example video with `description="My Task #{}"`, these all return
  results:
    Task.query.startswith(description='4')
    Task.query.like(description='*as')
    Task.query.endswith(description='sk')
    Task.query.startswith(description='Task')
    Task.query.startswith(description='M')


  These won't:
    # the '#' token is stripped in FULL_TEXT index, so won't find anything if
    # passed during query; you can use your own custom keygen to decide what
    # you want to search for
    Task.query.startswith(description='#4')

  Other queries that failed during the session may have failed because the data
  wasn't indexed / reindexed properly. See:
    https://josiahcarlson.github.io/rom/util.html#rom.util.refresh_indices
    https://josiahcarlson.github.io/rom/util.html#rom.util.show_progress

* For usernames, email addresses, and similar, where you don't want to mangle
  the data you want to query for (except for case-sensitivity maybe), the
  `rom.IDENTITY` and `rom.IDENTITY_CI` are probably what you're looking for:

    In [3]: rom.IDENTITY('MyUsername1')                                                                                     
    Out[3]: ['MyUsername1']

    In [4]: rom.IDENTITY_CI('MyUsername1')                                                                                  
    Out[4]: ['myusername1']

----

The below should serve as an updated example that addresses some of the
questions brought up in the video.

Thank you for recording the video Bruno! Thank you everyone else for watching
and reading!

'''

import rom
import datetime

rom.util.set_connection_settings(db=9)

class User(rom.Model):
    id = rom.PrimaryKey()
    username = rom.String(required=True, unique=True, keygen=rom.IDENTITY_CI, index=True)
    unsave_password = rom.String(required=True)
    tasks = rom.OneToMany('Task')
    created_at = rom.DateTime(default=datetime.datetime.now)

class Task(rom.Model):
    id = rom.PrimaryKey()
    description = rom.String(default=b'', index=True, keygen=rom.FULL_TEXT, prefix=True, suffix=True)
    is_done = rom.Boolean(default=False, index=True)
    user = rom.ManyToOne('User', on_delete='cascade')

# get_by() works on most simple indexes, and here we exploit the unique index
user = User.get_by(username=b'Bruno')
if not user:
    user = User(username=b'Bruno', unsave_password=b'bad_password')
    user.save()
    
    for i in range(10):
        task = Task(description="My Task #{}".format(i), user=user)
        task.save()
    rom.session.commit()

# these should all produce results
for task in Task.query.startswith(description='4'):
    print("got task startswith number:", task.description)

for task in Task.query.endswith(description='4'):
    print("got task endswith number:", task.description)

for task in Task.query.like(description='*as'):
    print("got task like:", task.description)

for task in Task.query.endswith(description='sk'):
    print("got task endswith:", task.description)

for task in Task.query.startswith(description='Task'):
    print("got task startswith uppercased 1:", task.description)

for task in Task.query.startswith(description='M'):
    print("got task startswith uppercased 2:", task.description)

for user in User.query.all():
    user.delete()
for task in Task.query.all():
    task.delete()