Oracle数据库随机取某条记录的一个字段值

思路：

先将取出的值随机排序，然后在随机排序的每次取第一条的结果

举例如下：

select * from(select t.code fromTBIZOPS_PROVINCE  t ORDER BY DBMS_RANDOM.RANDOM())where rownum < 2;
select * from (select t.code from TBIZOPS_CITY t wheret.province_id = '13' ORDER BY DBMS_RANDOM.RANDOM()) where rownum< 2 ;
select * from (select t.code from TBIZOPS_County t wheret.province_id = '13' and t.city_id = '1304'ORDER BYDBMS_RANDOM.RANDOM()) where rownum < 2 ;