如何获得每个季度的运行总计，而不是重复值为 0。使用 SQL Server 2012

Question

我需要计算每个季度的总保费。但是我的数据是按日期细分的。

所以我需要基于年份和季度的第一行显示值，但是如果后面的行具有相同的Year 和Quarter，那么值应该是 0。

这就是现在的样子：

但我需要这样：

使用虚拟数据查询：

declare @TempTable1 table (ID int, Date date, PolicyNumber varchar(100), Premium money)

insert into @TempTable1 
values (1, '2018-01-01', 'Policy1', 100),
       (2, '2018-02-08', 'Policy2', 200),
       (3, '2018-04-15', 'Policy3', 300),
       (4, '2018-05-31', 'Policy4', 150),
       (5, '2018-07-10', 'Policy5', 250),
       (6, '2018-11-23', 'Policy6', 350),
       (7, '2018-12-05', 'Policy7', 330),
       (8, '2019-01-09', 'Policy8', 140),
       (9, '2019-06-18', 'Policy9', 225),
       (10, '2019-06-28', 'Policy10', 145)

SELECT  
    ID, 
    Date, 
    PolicyNumber,    
    YEAR(date) AS Year, 
    DATEPART(qq, date) AS Quarter,
    Premium,
    SUM(premium) OVER (ORDER BY YEAR(date), DATEPART(qq, date)) AS RunningTotal
FROM
    @TempTable1

是否有可能在同一个SELECT 语句中实现这一点？

谢谢

Answer 1

试试这个。它为每个年份和季度分区创建一个 row_number，并且只允许 row = 1 的计算值

SELECT ID,
        Date,
        policynumber, 
        dq2.year,
        dq2.Quarter,
        premium,
        case when rn=1 then runningtotal else 0 end 'runningtotal' 
from
    (
        select *,row_number() OVER (partition by year,quarter order by policynumber) as RN FROM
        (
        select  ID, 
                Date, 
                PolicyNumber,    
                Year(date) as 'Year', 
                DATEPART(qq,date) as [Quarter],
                Premium,
                sum(premium) over (order by Year(date),DATEPART(qq,date)) as RunningTotal

        from @TempTable1
        ) DQ
    ) DQ2

Answer 2

您需要做的就是通过lag() 窗口函数添加检查Year/Quarter 是否正在更改。

select  ID, 
        Date, 
        PolicyNumber,    
        Year(date) as Year, 
        DATEPART(qq,date) as Quarter,
        Premium,
        case when lag(DATEPART(qq,date), 1, null) over (order by Year(date),DATEPART(qq,date)) - DATEPART(qq,date) = 0 then 0 else
        sum(premium) over (order by Year(date),DATEPART(qq,date)) end as RunningTotal
from @TempTable1

我建议将初始计算列包装在子查询中，以减少所涉及的 datepart() 计算的数量，但任一解决方案都可以。

子查询选项：

select a.ID
, a.Date
, a.PolicyNumber
, a.Year
, a.Quarter
, a.Premium
, case when lag(a.Quarter, 1, null) over (order by a.Year,a.Quarter) - a.Quarter = 0 then 0 else
            sum(a.premium) over (order by a.Year,a.Quarter) end as RunningTotal
from (
    select  ID, 
            Date, 
            PolicyNumber,    
            Year(date) as Year, 
            DATEPART(qq,date) as Quarter,
            Premium
    from @TempTable1
    ) as a