PROCEDURE construire_tabela( f_nume_tabela VARCHAR2) IS n NUMBER;
BEGIN
SELECT COUNT(*) INTO n FROM user_tables WHERE table_name = f_nume_tabela;
IF n=0 THEN
EXECUTE IMMEDIATE 'create table ' || f_nume_tabela || '(n number)';
ELSE
EXECUTE IMMEDIATE 'drop table' || f_nume_tabela;
END IF;
END construire_tabela;