drop table tresultat purge;
create table tresultat(ligne varchar2(200));

variable vidterrain char(2);
prompt id terrain?
accept vidterrain

declare
didterrain char(2):='&vidterrain';
didReserv char(3);
ddateReserv date;
dmessage varchar2(200);
inexistant exception;
probleme exception;
dcpt number;
dcptReserv number;
begin
	
	dmessage:='terrain inconnu';
	select count(*) into dcpt
		from terrain
		where idterrain=didterrain;
	if dcpt=0
	then raise inexistant;
	else select count(*) into dcptReserv
		from terrain T, reservation R
		where T.idterrain=R.idterrain
		and R.dateReserv >= sysdate;
		dmessage:='Impossible, il existe des réservations faites par ce terrain pour aujourd''hui ou dans le futur';
		if dcptReserv>0
		then raise probleme;
		else select count(*) into dcptReserv
		from terrain T, reservation R
		where T.idterrain=R.idterrain
		and R.dateReserv < sysdate;
		if dcptReserv>0
		then delete from reservation
		where idterrain=didterrain;
		insert into tresultat values(to_char(dcptReserv)||' action(s) de réservations faites dans le passé par ce terrain ont été supprimées');
		end if;
		delete from terrain where idterrain=didterrain;
		insert into tresultat values('terrain supprimé');
		commit;
		end if;	
	end if;
	exception
	when inexistant then insert into tresultat values (dmessage);
	when probleme then insert into tresultat values (dmessage);
end;
.
/
select * from tresultat;