SELECT count(*) FROM battle WHERE id NOT IN ( SELECT lost_in_battle FROM ship WHERE tonnage  =  '225' );
How many battles did not lose any ship with tonnage '225'?
SELECT count ( * ) FROM battle WHERE id NOT IN ( SELECT lost_in_battle FROM ship WHERE tonnage = '225 ' ) ;
select count ( * ) from battle where id not in ( select lost_in_battle from ship where tonnage = value )
How many battles did not lose any ship with tonnage '225 ' ?