从两个相同字段的数据表分别随机选出20条数据，然后随机排序，怎么操作？

[sinat_35520452]

表1 zhongwen
表2 zhongwen2 两个表字段一样的
从 表1 zhongwen 随机选30条数据，select * from zhongwen order by rand() limit 0,30");
从 表2 zhongwen2 随机选20条数据，select * from zhongwen2 order by rand() limit 0,20");

然后把这20条记录随机混合 ，显示出来，
怎么操作

[sinat_35520452]

然后把这50条记录随机混合 ，显示出来， 怎么操作

[二月十六]

仅供参考：

SELECT * FROM(
(SELECT * from zhongwen  order by rand() limit 0,30)
UNION
(select * from zhongwen2  order by rand() limit 0,20) t order by rand()

[sinat_35520452]

SELECT * FROM( (SELECT * from zhongwen order by rand() limit 0,50) UNION (select * from zhongwen2 order by rand() limit 0,20)) t order by rand()