def test_not_expression(self):
s = 'NOT foo = "bar"'
clause = build_expression_from_tokens(s.split())
self.assertIsInstance(clause, NotExpression)
expr = clause.expression
self.assertIsInstance(expr, EqualsExpression)
self.assertEqual(expr.fieldname, 'foo')
self.assertEqual('bar', expr.value)
def test_and_expression(self):
s = 'a > 1 AND b = 0'
clause = build_expression_from_tokens(s.split())
self.assertIsInstance(clause, AndExpression)
lhs, rhs = clause.left, clause.right
self.assertIsInstance(lhs, GreaterThanExpression)
self.assertIsInstance(rhs, EqualsExpression)
self.assertEqual(lhs.fieldname, 'a')
self.assertEqual(rhs.value, 0)
def test_equals_expression(self):
s = 'a = 1'
clause = build_expression_from_tokens(s.split())
self.assertIsInstance(clause, EqualsExpression)
self.assertEqual(clause.fieldname, 'a')
self.assertEqual(clause.value, 1)
def test_greater_than(self):
s = 'a > 1'
clause = build_expression_from_tokens(s.split())
self.assertIsInstance(clause, GreaterThanExpression)
self.assertEqual(clause.fieldname, 'a')
self.assertEqual(clause.value, 1)
def test_boolean_expression(self):
s = 'foo = False'
clause = build_expression_from_tokens(s.split())
self.assertIsInstance(clause, EqualsExpression)
self.assertEqual(clause.fieldname, 'foo')
self.assertEqual(clause.value, False)
def validate(self):
self.filter_criteria = build_expression_from_tokens(
self.expression_buffer)
if not self.filter_criteria:
raise ValueError('No filter criteria given for where clause')