oracle random

---order  by  每次结果都不一样噢

SELECT  *from t_aa order by dbms_random.value

SELECT  *from t_aa order by dbms_random.value() 
SELECT  *from t_aa order by dbms_random.random() 

select    trunc (dbms_random.value(1,10) )    from dual  1-10之间任意数字 

用法是DBMS_RANDOM.STRING(选项, 返回字符串长度)

选项有如下几种可供选择：
1）'u', 'U' - returning string in uppercase alpha characters
2）'l', 'L' - returning string in lowercase alpha characters
3）'a', 'A' - returning string in mixed case alpha characters
4）'x', 'X' - returning string in uppercase alpha-numeric characters
5）'p', 'P' - returning string in any printable characters.
6）Otherwise the returning string is in uppercase alpha characters.

select    dbms_random.string('U',2)           from dual --任意字符