how many ship there
select count ( * ) from ship
what is the name of ship id 2
select name from ship where ship_id = 2
what is the built year of the ship id 3
select built_year from ship where ship_id = 3
what is the class of the ship id 1
select class from ship where ship_id = 1
what is the flag of the ship id 1
select flag from ship where ship_id = 1