Question

我有这个数据集，我有一个YYYYMM格式的时间序列。我有两列基本上作为真/假标志。我想基于这些检索当前范围的真/假标志添加两个额外的列：

        Default  Cure
201301  0        NULL
201302  0        NULL
201303  0        NULL
201304  1        NULL
201305  1        NULL
201306  1        NULL
201307  1        NULL
201308  NULL     0
201309  NULL     0
201310  NULL     1
201311  0        NULL
201312  0        NULL
201401  0        NULL
201402  0        NULL
201403  1        NULL
201404  1        NULL
201405  0        NULL
201406  0        NULL
201407  NULL     1
201408  NULL     0
201409  NULL     0
201410  NULL     0
201411  NULL     0
201412  NULL     0

在此数据集中，您可以看到在201304,05,06,07期间将默认列设置为1，并且在201310期间将Cure列设置为1.

这基本上意味着默认时间序列从201304期到201310期间有效。最终我想生成以下集：

        Default  Cure  DefaultPeriod  CurePeriod
201301  0        NULL  NULL           NULL
201302  0        NULL  NULL           NULL
201303  0        NULL  NULL           NULL
201304  1        NULL  201304         201310
201305  1        NULL  201304         201310
201306  1        NULL  201304         201310
201307  1        NULL  201304         201310
201308  NULL     0     201304         201310
201309  NULL     0     201304         201310
201310  NULL     1     201304         201310
201311  0        NULL  NULL           NULL
201312  0        NULL  NULL           NULL
201401  0        NULL  NULL           NULL
201402  0        NULL  NULL           NULL
201403  1        NULL  201403         201407
201404  1        NULL  201403         201407
201405  0        NULL  201403         201407
201406  0        NULL  201403         201407
201407  NULL     1     201403         201407
201408  NULL     0     NULL           NULL
201409  NULL     0     NULL           NULL
201410  NULL     0     NULL           NULL
201411  NULL     0     NULL           NULL
201412  NULL     0     NULL           NULL

可能会出现多个范围，但它们不能重叠。我将如何实现这一目标。我曾尝试在同一张桌子上进行各种最小/最大周期加入，但我似乎找不到合适的解决方案。

Answer 1

这是一位真正的思想家：）

基本上我在“治愈”日期（c1）上划分数据，为每个组编号（c2），然后在每个组中查找分钟和最大值（c3 C4），然后应用一些逻辑来过滤掉行在分钟之前来临。

declare @t table
(
    [Month] varchar(6),
    [Default] bit,
    [Cure] bit
);

insert into @t values('201301',  0,        NULL);
insert into @t values('201302',  0,        NULL);
insert into @t values('201303',  0,        NULL);
insert into @t values('201304',  1,        NULL);
insert into @t values('201305',  1,        NULL);
insert into @t values('201306',  1,        NULL);
insert into @t values('201307',  1,        NULL);
insert into @t values('201308',  NULL,     0);
insert into @t values('201309',  NULL,     0);
insert into @t values('201310',  NULL,     1);
insert into @t values('201311',  0,        NULL);
insert into @t values('201312',  0,        NULL);
insert into @t values('201401',  0,        NULL);
insert into @t values('201402',  0,        NULL);
insert into @t values('201403',  1,        NULL);
insert into @t values('201404',  1,        NULL);
insert into @t values('201405',  0,        NULL);
insert into @t values('201406',  0,        NULL);
insert into @t values('201407',  NULL,     1);
insert into @t values('201408',  NULL,     0);
insert into @t values('201409',  NULL,     0);
insert into @t values('201410',  NULL,     0);
insert into @t values('201411',  NULL,     0);
insert into @t values('201412',  NULL,     0);


with c1 as
(
    select min([Month]) [Month], 1 x from @t
    union all 
    select [Month],1 from @t
    where Cure = 1
),
c2 as 
(
    select t.[Month],[Default],[Cure],
        sum(x) over (order by t.[Month] rows between unbounded preceding and 1 preceding) grp
    from @t t
    left outer join c1 on c1.[Month] = t.[Month]
),
c3 as
(
    select grp, min([Month]) [Month]
    from c2
    where [Default] = 1
    group by grp
),
c4 as 
(
    select grp, max([Month]) [Month]
    from c2
    where [Cure] = 1
    group by grp
)
select c2.[Month], c2.[Default], c2.[Cure], 
    case when c2.[Month] >= c3.[Month] then c3.[Month] else null end as DefaultPeriod,
    case when c2.[Month] >= c3.[Month] then c4.[Month] else null end as CurePeriod
from c2
left outer join c3 on c2.grp = c3.grp
left outer join c4 on c2.grp = c4.grp

T-SQL：时间序列填充范围

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