Oracle的随机数、随机日期和时间、随机字符串

1. 随机数包 
SELECT DBMS_RANDOM.VALUE 
  from DUAL; 
2. 在[0..100]范围内取随机数 
SELECT TRUNC (DBMS_RANDOM.VALUE (0, 100)) 
  from DUAL; 
3. 大于字符‘A’的10个字符随机字符串 
SELECT DBMS_RANDOM.STRING (’A’, 10) 
  from DUAL; 
4. 单个小写随机字符 
SELECT CHR (ROUND (DBMS_RANDOM.VALUE (97, 122))) 
  from DUAL; 
5. 在过去10天内取随机日期 
SELECT TO_DATE (TRUNC (DBMS_RANDOM.VALUE (TO_NUMBER (TO_CHAR (SYSDATE - 10, 
                                                              ’J’ 
                                                             ) 
                                                    ), 
                                          TO_NUMBER (TO_CHAR (SYSDATE, ’J’))