求助：如何从两张表中同时取数据

ccb_bee

两张表的结构一样，
select * from tab1 where date="20080701" order by date;
select * from tab2 where date="20080701" order by date;

我想用一个语句就完成以上功能,请问该如何写这个sql?

xxyyy

滤掉重复行：
select * from tab1 where date="20080701" order by date;
union
select * from tab2 where date="20080701" order by date;

保留所有行：
select * from tab1 where date="20080701" order by date;
union all
select * from tab2 where date="20080701" order by date;