如何編寫一個sql查詢以獲得來自1個表的以下結果？

Question

如何編寫一個查詢得到以下的輸出：

主表/源表：

Answer 1

下面是一個使用union all和聚集了一個方法：

select weeknumber, sum(opened) as opened, sum(closed) as closed 
from ((select OpenWeekNumber as weeknumber, 1 as Opened, 0 as Closed 
     from maintable 
    ) union all 
     (select ClosedWeekNumber as weeknumber, 0 as Opened, 1 as Closed 
     from maintable 
     where ClosedWeekNumber > 0 
    ) 
    ) t 
group by weeknumber 
order by weeknumber;