The predicate expression to use in combination with the Relations in this bucket.

The relation collection with EntityRelation objects which is used in combination with the PredicateExpression in this bucket

Optional alias for select list fields. Used in entity fetches where the entity type to fetch has to be aliased because the source of the data is a derived table or requires aliasing because the relations used require that. If specified, all predicates referring to the entity type to fetch have to use the same alias.