有効期間 - SQLのVIEW

Question

私はこのようなデータを持つ2つのテーブル（実際にそこ4がありますが、今のところ、それは2だと言うことができます）があります。

Table PersonA 
ClientID ID From  Till 
1   10 1.1.2017 30.4.2017 
1   12 1.8.2017 2.1.2018 

Table PersonB  
ClientID ID From  Till 
1   6 1.3.2017 30.6.2017 

をそして、私はこのような何かを示すだろうビューを生成する必要があります：

ClientID  From  Till  PersonA  PersonB 
1    1.1.2017 28.2.2017 10   NULL 
1    1.3.2017 30.4.2017 10   6 
1    1.5.2017 30.6.2017 NULL   6 
1    1.8.2017 02.1.2018 12   NULL 

したがって、基本的に私は、各クライアントが与えられた期間中に持っていた "人"を示すビューを作成する必要があります。
重複がある場合、クライアントはPersonAとPersonBの両方を持ちます（PersonCとPersonDにも同じことが適用されます）。
最後のビューでは、1つのクライアントに重複する日付を設定することはできません。

私はこれにどのようにアプローチするのか分かりません。

Answer 1

this algorithmの適応では、我々はすでに重複を扱うことができます。質問に与えられたわずか2つのPersonテーブルと

declare @PersonA table(ClientID int, ID int, [From] date, Till date); 
insert into @PersonA values (1,10,'20170101','20170430'),(1,12,'20170801','20180112'); 

declare @PersonB table(ClientID int, ID int, [From] date, Till date); 
insert into @PersonB values (1,6,'20170301','20170630'); 

declare @PersonC table(ClientID int, ID int, [From] date, Till date); 
insert into @PersonC values (1,12,'20170401','20170625'); 

declare @PersonD table(ClientID int, ID int, [From] date, Till date); 
insert into @PersonD values (1,14,'20170501','20170525'),(1,14,'20170510','20171122'); 

with X(ClientID,EdgeDate) 
    as (select ClientID 
       ,case 
        when toggle = 1 
         then Till 
        else [From] 
       end as EdgeDate 
     from 
       (
       select ClientID,[From],Till from @PersonA 
       union all 
       select ClientID,[From],Till from @PersonB 
       union all 
       select ClientID,[From],Till from @PersonC 
       union all 
       select ClientID,[From],Till from @PersonD 
      ) as concated 
      cross join 
       (
       select-1 as toggle 
       union all 
       select 1 as toggle 
      ) as toggler 
),merged 
    as (select distinct 
       S.ClientID 
       ,S.EdgeDate as [From] 
       ,min(E.EdgeDate) as Till 
     from 
       X as S 
      inner join X as E 
       on S.ClientID = E.ClientID 
        and S.EdgeDate < E.EdgeDate 
     group by S.ClientID 
       ,S.EdgeDate 
),prds 
    as (select distinct 
       merged.ClientID 
       ,merged.[From] 
       ,merged.Till 
       ,A.ID as PersonA 
       ,B.ID as PersonB 
       ,C.ID as PersonC 
       ,D.ID as PersonD 
     from 
       merged 
      left join @PersonA as A 
       on merged.ClientID = A.ClientID 
        and A.[From] <= merged.[From] 
        and merged.Till <= A.Till 
      left join @PersonB as B 
       on merged.ClientID = B.ClientID 
        and B.[From] <= merged.[From] 
        and merged.Till <= B.Till 
      left join @PersonC as C 
       on merged.ClientID = C.ClientID 
        and C.[From] <= merged.[From] 
        and merged.Till <= C.Till 
      left join @PersonD as D 
       on merged.ClientID = D.ClientID 
        and D.[From] <= merged.[From] 
        and merged.Till <= D.Till 
     where not(A.ID is null 
        and B.ID is null 
        and C.ID is null 
        and D.ID is null 
       ) 
) 
select ClientID 
    ,[From] 
    ,case 
     when Till = lead([From] 
       ) over(order by Till) 
      then dateadd(d,-1,Till) 
     else Till 
    end as Till 
    ,PersonA 
    ,PersonB 
    ,PersonC 
    ,PersonD 
from 
    prds 
order by ClientID 
     ,[From] 
     ,Till; 

出力：スクリプトの

+----------+------------+------------+---------+---------+ 
| ClientID | From | Till | PersonA | PersonB | 
+----------+------------+------------+---------+---------+ 
|  1 | 2017-01-01 | 2017-02-28 | 10  | NULL | 
|  1 | 2017-03-01 | 2017-04-29 | 10  | 6  | 
|  1 | 2017-04-30 | 2017-06-30 | NULL | 6  | 
|  1 | 2017-08-01 | 2018-01-12 | 12  | NULL | 
+----------+------------+------------+---------+---------+ 

出力、それは上記のようです

+----------+------------+------------+---------+---------+---------+---------+ 
| ClientID | From | Till | PersonA | PersonB | PersonC | PersonD | 
+----------+------------+------------+---------+---------+---------+---------+ 
|  1 | 2017-01-01 | 2017-02-28 | 10  | NULL | NULL | NULL | 
|  1 | 2017-03-01 | 2017-03-31 | 10  | 6  | NULL | NULL | 
|  1 | 2017-04-01 | 2017-04-29 | 10  | 6  | 12  | NULL | 
|  1 | 2017-04-30 | 2017-04-30 | NULL | 6  | 12  | NULL | 
|  1 | 2017-05-01 | 2017-05-09 | NULL | 6  | 12  | 14  | 
|  1 | 2017-05-10 | 2017-05-24 | NULL | 6  | 12  | 14  | 
|  1 | 2017-05-25 | 2017-06-24 | NULL | 6  | 12  | 14  | 
|  1 | 2017-06-25 | 2017-06-29 | NULL | 6  | NULL | 14  | 
|  1 | 2017-06-30 | 2017-07-31 | NULL | NULL | NULL | 14  | 
|  1 | 2017-08-01 | 2017-11-21 | 12  | NULL | NULL | 14  | 
|  1 | 2017-11-22 | 2018-01-12 | 12  | NULL | NULL | NULL | 
+----------+------------+------------+---------+---------+---------+---------+