'Add missing table SELECT and JOIN clause to ``query`` for reaching the parent table (no duplicates)
:param current_model: current model object
:param parent_model_name: name of the parent model for which the clauses should be added
:param query: query object on which the JOIN should be added'

def _inherits_join_add(self, current_model, parent_model_name, query):

    inherits_field = current_model._inherits[parent_model_name]
    parent_model = self.env[parent_model_name]
    (parent_alias, parent_alias_statement) = query.add_join((current_model._table, parent_model._table, inherits_field, 'id', inherits_field), implicit=True)
    return parent_alias
