Sql 当涉及日期列时，如何在Case语句中处理聚合函数

我正在计算invoiceDate vs currentDate，然后按客户分组求和值/金额列，但返回的“invoiceDate不包含在聚合函数或GROUP by子句中”

选择客户
案例
当datediff（dd、InvoiceDate、getdate（））需要条件聚合时：

select Customer     
       sum(case when datediff(day, InvoiceDate, getdate()) <= 30
                then InvoiceBal1 else 0
           end) as balance_current
       sum(case when datediff(day, InvoiceDate, getdate()) between 31 and 60
                then InvoiceBal1 else 0
           end) as balance_30days
from CusInvoice
group by Customer

选择客户
求和（datediff（day、InvoiceDate、getdate（））需要条件聚合时的大小写）

select Customer     
       sum(case when datediff(day, InvoiceDate, getdate()) <= 30
                then InvoiceBal1 else 0
           end) as balance_current
       sum(case when datediff(day, InvoiceDate, getdate()) between 31 and 60
                then InvoiceBal1 else 0
           end) as balance_30days
from CusInvoice
group by Customer

选择客户
总和（datediff（day、InvoiceDate、getdate（）时的大小写）你的问题被标记为MySQL，但你的代码看起来更像SQL Server。我更改了标记。你的问题被标记为MySQL，但你的代码看起来更像SQL Server。我更改了标记。嗨@Ronald，接受答案可能是感谢的好方法。嗨@Ronald，接受答案可能是感谢的好方法。