def _get_collection(model, insecure=False, limit=None, marker=None,
sort_keys=None, sort_dirs=None, fields=None, **filters):
columns = (
tuple([getattr(model, f) for f in fields if hasattr(model, f)])
if fields else ()
)
query = (db_base.model_query(model, columns) if insecure
else _secure_query(model, *columns))
query = db_filters.apply_filters(query, model, **filters)
query = _paginate_query(
model,
limit,
marker,
sort_keys,
sort_dirs,
query
)
try:
return query.all()
except Exception as e:
raise exc.DBError(
"Failed when querying database, error type: %s, "
"error message: %s" % (e.__class__.__name__, str(e))
)
def conditional_update(model, values, expected_values, insecure=False,
filters=None, session=None):
"""Compare-and-swap conditional update SQLAlchemy implementation."""
filters = filters or {}
filters.update(expected_values)
query = (db_base.model_query(model) if insecure else _secure_query(model))
query = db_filters.apply_filters(query, model, **filters)
update_args = {'synchronize_session': False}
# Return True if we were able to change any DB entry, False otherwise
result = query.update(values, **update_args)
return 0 != result