"""This series of tests illustrates different ways to SELECT a single
record by primary key
"""
import random
from sqlalchemy import bindparam
from sqlalchemy import Column
from sqlalchemy import create_engine
from sqlalchemy import Identity
from sqlalchemy import Integer
from sqlalchemy import select
from sqlalchemy import String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.future import select as future_select
from sqlalchemy.orm import deferred
from sqlalchemy.orm import Session
from . import Profiler
Base = declarative_base()
engine = None
ids = range(1, 11000)
class Customer(Base):
__tablename__ = "customer"
id = Column(Integer, Identity(), primary_key=True)
name = Column(String(255))
description = Column(String(255))
q = Column(Integer)
p = Column(Integer)
x = deferred(Column(Integer))
y = deferred(Column(Integer))
z = deferred(Column(Integer))
Profiler.init("short_selects", num=10000)
@Profiler.setup
def setup_database(dburl, echo, num):
global engine
engine = create_engine(dburl, echo=echo, query_cache_size=0)
Base.metadata.drop_all(engine)
Base.metadata.create_all(engine)
sess = Session(engine)
sess.add_all(
[
Customer(
id=i,
name="c%d" % i,
description="c%d" % i,
q=i * 10,
p=i * 20,
x=i * 30,
y=i * 40,
)
for i in ids
]
)
sess.commit()
@Profiler.profile
def test_orm_query_classic_style(n):
"""classic ORM query of the full entity, no cache"""
session = Session(bind=engine)
for id_ in random.sample(ids, n):
session.query(Customer).filter(Customer.id == id_).one()
@Profiler.profile
def test_orm_query_classic_style_w_cache(n):
"""classic ORM query of the full entity, using cache"""
cache = {}
session = Session(bind=engine.execution_options(compiled_cache=cache))
for id_ in random.sample(ids, n):
session.query(Customer).filter(Customer.id == id_).one()
@Profiler.profile
def test_orm_query_new_style(n):
"""new style ORM select() of the full entity, no cache."""
session = Session(bind=engine)
for id_ in random.sample(ids, n):
stmt = future_select(Customer).where(Customer.id == id_)
session.execute(stmt).scalar_one()
@Profiler.profile
def test_orm_query_new_style_cache(n):
"""new style ORM select() of the full entity, using cache."""
cache = {}
session = Session(bind=engine.execution_options(compiled_cache=cache))
for id_ in random.sample(ids, n):
stmt = future_select(Customer).where(Customer.id == id_)
session.execute(stmt).scalar_one()
@Profiler.profile
def test_orm_query_classic_style_cols_only(n):
"""classic ORM query against columns, no cache"""
session = Session(bind=engine)
for id_ in random.sample(ids, n):
session.query(Customer.id, Customer.name, Customer.description).filter(
Customer.id == id_
).one()
@Profiler.profile
def test_orm_query_classic_style_cols_only_cache(n):
"""classic ORM query against columns, using cache"""
cache = {}
session = Session(bind=engine.execution_options(compiled_cache=cache))
for id_ in random.sample(ids, n):
session.query(Customer.id, Customer.name, Customer.description).filter(
Customer.id == id_
).one()
@Profiler.profile
def test_core_new_stmt_each_time(n):
"""test core, creating a new statement each time, no cache"""
with engine.connect() as conn:
for id_ in random.sample(ids, n):
stmt = select(Customer.__table__).where(Customer.id == id_)
row = conn.execute(stmt).first()
tuple(row)
@Profiler.profile
def test_core_new_stmt_each_time_compiled_cache(n):
"""test core, creating a new statement each time, using cache"""
compiled_cache = {}
with engine.connect().execution_options(
compiled_cache=compiled_cache
) as conn:
for id_ in random.sample(ids, n):
stmt = select(Customer.__table__).where(Customer.id == id_)
row = conn.execute(stmt).first()
tuple(row)
@Profiler.profile
def test_core_reuse_stmt(n):
"""test core, reusing the same statement, no cache"""
stmt = select(Customer.__table__).where(Customer.id == bindparam("id"))
with engine.connect() as conn:
for id_ in random.sample(ids, n):
row = conn.execute(stmt, {"id": id_}).first()
tuple(row)
@Profiler.profile
def test_core_reuse_stmt_compiled_cache(n):
"""test core, reusing the same statement, using cache"""
stmt = select(Customer.__table__).where(Customer.id == bindparam("id"))
compiled_cache = {}
with engine.connect().execution_options(
compiled_cache=compiled_cache
) as conn:
for id_ in random.sample(ids, n):
row = conn.execute(stmt, {"id": id_}).first()
tuple(row)
if __name__ == "__main__":
Profiler.main()