import os

import sqlalchemy

from sqlalchemy import orm

from models import Zebra, WateringHole

from utils import now, YEAR, step, configure_logger

# Comment out these instructions because once you use echo=True once it wrecks

# it for everyone and we can't use our custom logger.

"""

# Configure a connection to the database at the URL specified by the

# DATABASE_URL environment variable.

# Remember that we're using `echo=True` so we can see all generated SQL.

engine = sqlalchemy.create_engine(os.environ['DATABASE_URL'], echo=True)

# Create a session factory. Calling `Session()` will create new SQLAlchemy

# ORM sessions.

Session = orm.sessionmaker(bind=engine)

# Create a new session which we'll use for the following investigation.

session = Session()

"""

with step():

configure_logger()

engine = sqlalchemy.create_engine(os.environ['DATABASE_URL'])

Session = orm.sessionmaker(bind=engine)

session = Session()

with step():

q = session.query(Zebra).filter(Zebra.when_born <= now() - 2*YEAR)

old_zebra = q.first()

with step():

wh = session.query(WateringHole).first()

with step():

session.rollback()

# Commit instead

with step():

session = Session()

# Grab any ol' Zebra

print(session.query(Zebra).first())

session.commit()