ORACLE从表中随机返回n条记录

使用ORDER BY子句，ROWNUM内置函数和DBMS_RANDOM包中的内置函数VALUE来实现

SQL> select * from 2 ( 3 select ename,job 4 from emp 5 order by dbms_random.value() 6 ) 7 where rownum<=5;ENAME JOB---------- ---------TURNER SALESMANSMITH CLERKMARTIN SALESMANBLAKE MANAGERSCOTT ANALYSTSQL> /ENAME JOB---------- ---------ALLEN SALESMANSMITH CLERKWARD SALESMANMARTIN SALESMANSCOTT ANALYST