通过case when实现SQL 多个字段合并为一列值

with tt as  
(select  A.GID,
 CASE  WHEN A.IsApp='是' THEN 'APP' else '' end 'APP',
CASE  WHEN A.IsSmallApp='是' THEN '小程序' else '' end 'SmallApp' from  Order  A
)
select   A.SalePrice,A.SaleStatus,
--销售参与渠道
--(A.IsApp+','+A.IsSmallApp),
--CASE  WHEN A.IsApp='是' THEN 'APP' else '' end 'APP',
--CASE  WHEN A.IsSmallApp='是' THEN '小程序' else '' end 'SmallApp',
(TT.APP+','+TT.SmallApp) as ChannelType,
--销售参与渠道
detail.SumQty--销售总数
from order (nolock)   A
INNER JOIN  orderdetail (nolock) B  ON A.Gid=B.orderGid
LEFT JOIN (select orderGid,  sum(ISNULL (SaleQty,0)) AS  SumQty
from orderdetail (nolock)  group by orderGid) AS detail on a.Gid = detail.orderGid