how to return results from code block

How to return single row or results from code block executed using ADO.NET ExecuteQuery() method.

I tried

 

DO $$

declare

  i integer :=0;

 

begin

select i+1 as res1, i+2 as res2;

END$$;

 

but got error:

 

ERROR:  query has no destination for result data

 

How to return single row result from code pgsql  code block ?

 

Andrus.