__tablename__ = 'blogs'
id = sa.Column(sa.Integer, primary_key=True)
# lazy = True / 'joined' are the same
comments = sa.orm.relationship(lambda: Comment,
lazy='dynamic',
backref='blog')
class Comment(Base, MethodsMixin):
__tablename__ = 'comments'
id = sa.Column(sa.Integer, primary_key=True)
blog_id = sa.Column(sa.ForeignKey(Blog.id, ondelete='cascade'),
nullable=False)
init_entities(Blog, Comment)
enable_logging()
sess = Session()
profiler = sqltap.ProfilingSession()
with profiler:
for b in sess.query(Blog):
assert b.comments.order_by('id').all()
query_stats = profiler.collect()
assert len(query_stats) == 3
from dateutil import parser
from sqlalchemy import inspect
from models import Zebra
from utils import step, configure_logger, Session, silence
configure_logger()
with step():
session = Session()
# Grab any ol' Zebra
zebra = session.query(Zebra).first()
session.commit()
with step():
print(f'Hello, {zebra.name}!')
# Don't show this
with silence():
session.close()
# JUST FOR MY OWN VERIFICATION: What happens when you rollback?
with step():
session = Session()
# Grab any ol' Zebra
print(session.query(Zebra).first())
# Rollback instead of commit
session.rollback()
print(f'Hello, {zebra.name}!')
with step():
