ISNULL(SUM(MyTable.Total),0) AS Total
如何修改上述语句也检查Total是否小于0(零),如果Total为NULL或小于0(否定),则将0分配给Total
CASE WHEN ISNULL(SUM(MyTable.Total),0) <= 0 THEN 0 ELSE SUM(MyTable.Total) END AS Total