创建测试用表：
CREATE OR REPLACE VIEW V AS
SELECT 'a' AS c FROM dual
UNION ALL
SELECT 'b' AS c FROM dual
UNION ALL
SELECT 'c' AS c FROM dual
UNION ALL
SELECT 'd' AS c FROM dual
UNION ALL
SELECT 'e' AS c FROM dual;
SELECT * FROM v;
查询语句如下：
SELECT c
FROM (SELECT c FROM v ORDER BY DBMS_RANDOM.VALUE())
WHERE ROWNUM < 3;
查询结果如下：