select [字段名] from( select * from( select tab1.*,dbms_random.value rd from tab1)order by rd) where rownum<10 and not([你的条件]) union select [字段名] from tab1 where [你的条件]
select * from (select * from staff order by dbms_random.random) where rownum < 4 表示从STAFF表中随机取3条记录<转自 葛宏宾的专栏> http://www.cnblogs.com/binary/archive/2005/04/01/130552.html
select * from(
select tab1.*,dbms_random.value rd from tab1)order by rd)
where rownum<10 and not([你的条件])
union
select [字段名] from tab1 where [你的条件]
where rownum < 4
表示从STAFF表中随机取3条记录<转自 葛宏宾的专栏>
http://www.cnblogs.com/binary/archive/2005/04/01/130552.html