SQL DB2-根据条件汇总销售额

Question

我想在SQL DB2中表达以下内容。我想根据两个条件之一来加总销售价值。我认为我需要CASE语句，但不确定。让我知道伪代码是否清楚..

SELECT Total_Service_Starts, Total_Service_Stops            

If ServiceFile.SERVICE_START > 20200101
   Then Total_Service_Starts  = SUM(ServiceFile.Rate * ServiceFile.Units)   

If ServiceFile.SERVICE_STOP > 20200101
   Then Total_Service_Stops  = SUM (ServiceFile.Rate * ServiceFile.Units)

谢谢！

Answer 1

您是正确的，案例就是您想要的。这样尝试：

select
  sum(case when ServiceFile.SERVICE_START > 20200101
              then (ServiceFile.Rate * ServiceFile.Units)   
           else 0 end) as "TotalServiceStarts",
  sum(case when ServiceFile.SERVICE_STOP > 20200101
              then (ServiceFile.Rate * ServiceFile.Units)
           else 0 end) as "TotalServiceStops"
from ServiceFile
where service_start > 20200101
   or service_stop > 20200101;