diana fara after am facut si merge
problema e ca la update
UPDATE       StraziCanale
SET                zet = '233.067', northing = '685558.289', easting = '394544.947'
WHERE        (id_strada = 167) AND (variabil_cod = '3')
Column or expression 'zet' cannot be updated.

zet e coloana ce o adaug asa
   try
            {
                SqlCeCommand update_tabela = pCon.CreateCommand();
                update_tabela.CommandText = "alter table strazicanale add column zet numeric(5,3)";
                update_tabela.ExecuteNonQuery();
            }
            catch (SqlCeException excep)
            {
            }