"""Evluating SQL expressions on ORM objects"""
import sqlalchemy as sa
from sqlalchemy.test import testing
from sqlalchemy import String,Integer,select
from sqlalchemy.test.schema import Table
from sqlalchemy.test.schema import Column
from sqlalchemy.orm import mapper,create_session
from sqlalchemy.test.testing import eq_
from test.orm import _base
from sqlalchemy import and_,or_,not_
from sqlalchemy.orm import evaluator
compiler = evaluator.EvaluatorCompiler()
def eval_eq(clause, testcases=None):
evaluator = compiler.process(clause)
def testeval(obj=None, expected_result=None):
assert evaluator(obj) == expected_result, "%s != %r for %s with %r" % (evaluator(obj), expected_result, clause, obj)
if testcases:
for an_obj,result in testcases:
testeval(an_obj, result)
return testeval
class EvaluateTest(_base.MappedTest):
@classmethod
def define_tables(cls, metadata):
Table('users', metadata,
Column('id', Integer, primary_key=True),
Column('name', String(64)))
@classmethod
def setup_classes(cls):
class User(_base.ComparableEntity):
pass
@classmethod
@testing.resolve_artifact_names
def setup_mappers(cls):
mapper(User, users)
@testing.resolve_artifact_names
def test_compare_to_value(self):
eval_eq(User.name == 'foo', testcases=[
(User(name='foo'), True),
(User(name='bar'), False),
(User(name=None), None),
])
eval_eq(User.id < 5, testcases=[
(User(id=3), True),
(User(id=5), False),
(User(id=None), None),
])
@testing.resolve_artifact_names
def test_compare_to_none(self):
eval_eq(User.name == None, testcases=[
(User(name='foo'), False),
(User(name=None), True),
])
@testing.resolve_artifact_names
def test_boolean_ops(self):
eval_eq(and_(User.name == 'foo', User.id == 1), testcases=[
(User(id=1, name='foo'), True),
(User(id=2, name='foo'), False),
(User(id=1, name='bar'), False),
(User(id=2, name='bar'), False),
(User(id=1, name=None), None),
])
eval_eq(or_(User.name == 'foo', User.id == 1), testcases=[
(User(id=1, name='foo'), True),
(User(id=2, name='foo'), True),
(User(id=1, name='bar'), True),
(User(id=2, name='bar'), False),
(User(id=1, name=None), True),
(User(id=2, name=None), None),
])
eval_eq(not_(User.id == 1), testcases=[
(User(id=1), False),
(User(id=2), True),
(User(id=None), None),
])
@testing.resolve_artifact_names
def test_null_propagation(self):
eval_eq((User.name == 'foo') == (User.id == 1), testcases=[
(User(id=1, name='foo'), True),
(User(id=2, name='foo'), False),
(User(id=1, name='bar'), False),
(User(id=2, name='bar'), True),
(User(id=None, name='foo'), None),
(User(id=None, name=None), None),
])
|