def test_projection():
query = query_module.QueryOptions(projection=("a", "b"))
expected_pb = query_pb2.Query(projection=[
query_pb2.Projection(property=query_pb2.PropertyReference(
name="a")),
query_pb2.Projection(property=query_pb2.PropertyReference(
name="b")),
])
assert _datastore_query._query_to_protobuf(query) == expected_pb
def _query_to_protobuf(query):
"""Convert an NDB query to a Datastore protocol buffer.
Args:
query (query.QueryOptions): The query spec.
Returns:
query_pb2.Query: The protocol buffer representation of the query.
"""
query_args = {}
if query.kind:
query_args["kind"] = [query_pb2.KindExpression(name=query.kind)]
if query.projection:
query_args["projection"] = [
query_pb2.Projection(property=query_pb2.PropertyReference(
name=name)) for name in query.projection
]
if query.distinct_on:
query_args["distinct_on"] = [
query_pb2.PropertyReference(name=name)
for name in query.distinct_on
]
if query.order_by:
query_args["order"] = [
query_pb2.PropertyOrder(
property=query_pb2.PropertyReference(name=order.name),
direction=DOWN if order.reverse else UP,
) for order in query.order_by
]
filter_pb = query.filters._to_filter() if query.filters else None
if query.ancestor:
ancestor_pb = query.ancestor._key.to_protobuf()
ancestor_filter_pb = query_pb2.PropertyFilter(
property=query_pb2.PropertyReference(name="__key__"),
op=query_pb2.PropertyFilter.HAS_ANCESTOR,
)
ancestor_filter_pb.value.key_value.CopyFrom(ancestor_pb)
if filter_pb is None:
filter_pb = ancestor_filter_pb
elif isinstance(filter_pb, query_pb2.CompositeFilter):
filter_pb.filters.add(property_filter=ancestor_filter_pb)
else:
filter_pb = query_pb2.CompositeFilter(
op=query_pb2.CompositeFilter.AND,
filters=[
_filter_pb(filter_pb),
_filter_pb(ancestor_filter_pb),
],
)
if filter_pb is not None:
query_args["filter"] = _filter_pb(filter_pb)
if query.start_cursor:
query_args["start_cursor"] = query.start_cursor.cursor
if query.end_cursor:
query_args["end_cursor"] = query.end_cursor.cursor
query_pb = query_pb2.Query(**query_args)
if query.offset:
query_pb.offset = query.offset
if query.limit:
query_pb.limit.value = query.limit
return query_pb