c# - Group By 统计相同状态值的总数

Question

我有 2 个表，Order 和 Store。这是我需要的表中的一些字段。

订单表

  OrderId StoreId SystemOrderStatus
     1       1        Received
     2       1        Sent
     3       2        Complete
     4       2        Received

我怎样才能得到这个输出:

StoreId ReceivedStatusCount SentStatusCount CompleteStatusCount
     1            1                1                0
     2            1                0                1

谢谢。

Answer 1

只需使用case when，如下所示:

select
    StoreId,
    sum(case when SystemOrderStatus='Received' then 1 else 0 end) as ReceivedStatusCount,
    sum(case when SystemOrderStatus='Sent' then 1 else 0 end) as SentStatusCount,
    sum(case when SystemOrderStatus='Complete' then 1 else 0 end) as CompleteStatusCount
from
    "Order"
group by
    StoreId
order by
    StoreId