Mysql 多表合併統計

select count(*) ,t.warehouse , DATE_FORMAT(t.shipped_date, '%Y-%m-%d') shipped_date  from  
(	
	select order_no,warehouse,shipped_date,rowstate from customer_order_tab 
	union all 
	select order_no,warehouse,shipped_date,rowstate from customer_order_arc_tab 
) t
where t.rowstate in ('Delivered','Returned') 
group by  t.warehouse,DATE_FORMAT(t.shipped_date, '%Y-%m-%d')
order by t.shipped_date asc