'Returns a dictionary of {field_index: (field_index_other_table, other_table)}
representing all relationships to the given table. Indexes are 0-based.'

def get_relations(self, cursor, table_name):

    my_field_dict = self._name_to_index(cursor, table_name)
    constraints = self.get_key_columns(cursor, table_name)
    relations = {}
    for (my_fieldname, other_table, other_field) in constraints:
        other_field_index = self._name_to_index(cursor, other_table)[other_field]
        my_field_index = my_field_dict[my_fieldname]
        relations[my_field_index] = (other_field_index, other_table)
    return relations
