create or replace procedure pro_tableesists (v_table in varchar2) isv_num number;begin  select count(*) into v_num from user_objects where object_name=upper(v_table);  if  v_num>0 then     execute immediate  'drop table '||v_table;    end if;  end pro_tableesists ;

也可以 'drop table '||v_table||'purge;'