declare
v_11sql varchar2(2000) ;
CURSOR cur is select table_name from user_tables where table_name  order by table_name ;
begin
for rows in cur
loop
  v_11sql:= 'TRUNCATE TABLE ' || rows.table_name||';' ;
    dbms_output.put_line(v_11sql);

end loop;
end;

select table_name from user_tables order by table_name ;

如果执行不成功，直接使用 dbms_output.put_line 输出所需的sql再统一执行