

def find_ordering_name(self, name, opts, alias=None, default_order='ASC', already_seen=None):
    "\n        Returns the table alias (the name might be ambiguous, the alias will\n        not be) and column name for ordering by the given 'name' parameter.\n        The 'name' is of the form 'field1__field2__...__fieldN'.\n        "
    (name, order) = get_order_dir(name, default_order)
    pieces = name.split(LOOKUP_SEP)
    (field, cols, alias, joins, opts) = self._setup_joins(pieces, opts, alias)
    if (field.rel and (len(joins) > 1) and opts.ordering):
        if (not already_seen):
            already_seen = set()
        join_tuple = tuple([self.query.alias_map[j].table_name for j in joins])
        if (join_tuple in already_seen):
            raise FieldError('Infinite loop caused by ordering.')
        already_seen.add(join_tuple)
        results = []
        for item in opts.ordering:
            results.extend(self.find_ordering_name(item, opts, alias, order, already_seen))
        return results
    (cols, alias) = self._final_join_removal(cols, alias)
    return [(alias, cols, order)]

dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/Django-1.6.10/django/db/models/sql/compiler.py SQLCompiler.find_ordering_name/original