Você precisa obter os nomes das colunas primeiro. A maioria das plataformas suporta isso:
select column_name,ordinal_position
from information_schema.columns
where table_schema = ...
and table_name = ...
and ordinal_position <= 2
select column_name,ordinal_position
from information_schema.columns
where table_schema = ...
and table_name = ...
and ordinal_position <= 2