SELECT sum(SurfaceArea) FROM country WHERE Continent  =  "Asia" OR Continent  =  "Europe"
Give the total surface area covered by countries in Asia or Europe.
SELECT sum ( SurfaceArea ) FROM country WHERE Continent = `` Asia '' OR Continent = `` Europe ''
select sum ( surfacearea ) from country where continent = value or continent = value
Give the total surface area covered by countries in Asia or Europe .