def compile_targets(targets, environ):
"""Compile the targets and check for their validity. Process wildcard.
Args:
targets: A list of target expressions from the parser.
environ: A compilation context for the targets.
Returns:
A list of compiled target expressions with resolved names.
"""
# Bind the targets expressions to the execution context.
if isinstance(targets, query_parser.Wildcard):
# Insert the full list of available columns.
targets = [
query_parser.Target(query_parser.Column(name), None)
for name in environ.wildcard_columns
]
# Compile targets.
c_targets = []
target_names = set()
for target in targets:
c_expr = compile_expression(target.expression, environ)
target_name = find_unique_name(
target.name or query_parser.get_expression_name(target.expression),
target_names)
target_names.add(target_name)
c_targets.append(EvalTarget(c_expr, target_name, is_aggregate(c_expr)))
# Figure out if this query is an aggregate query and check validity of each
# target's aggregation type.
for index, c_target in enumerate(c_targets):
columns, aggregates = get_columns_and_aggregates(c_target.c_expr)
# Check for mixed aggregates and non-aggregates.
if columns and aggregates:
raise CompilationError(
"Mixed aggregates and non-aggregates are not allowed")
if aggregates:
# Check for aggregates of aggregates.
for aggregate in aggregates:
for child in aggregate.childnodes():
if is_aggregate(child):
raise CompilationError(
"Aggregates of aggregates are not allowed")
return c_targets
def test_binary(self):
self.assertEqual(
'and_account_date',
qp.get_expression_name(
qp.And(qp.Column('account'), qp.Column('date'))))
def test_unary(self):
self.assertEqual('not_account',
qp.get_expression_name(qp.Not(qp.Column('account'))))
def test_constant(self):
self.assertEqual('c17', qp.get_expression_name(qp.Constant(17)))
self.assertEqual(
'c2014_01_01',
qp.get_expression_name(qp.Constant(datetime.date(2014, 1, 1))))
def test_function(self):
self.assertEqual(
'length_date',
qp.get_expression_name(qp.Function('length', [qp.Column('date')])))
def test_column(self):
self.assertEqual('date', qp.get_expression_name(qp.Column('date')))
