insert into

   TB_TEST2

select

   to_char(rownum) c_id,

   sysdate + rownum / 24 / 3600 c_date,

   dbms_random.string('x', 20) c_string,

   trunc(dbms_random.value(0, 10000000)) c_amount,

   sys_guid() c_guid,

   to_char(trunc(dbms_random.value(0, 2))) as c_type

from

   dual connect by level <= 1000;