根據多列條件在同一個表內創建「集合」

Question

對於每個BoxId和Revision具有單個UnitTypeId爲1且單個UnitTypeId爲2且具有NULL SetNumber的唯一組合，分配SetNumber爲1.

表和數據設置：

IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[UnitTypes]') AND type in (N'U')) 
Drop Table dbo.UnitTypes 
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Tracking]') AND type in (N'U')) 
DROP TABLE [dbo].[Tracking] 
GO 
CREATE TABLE dbo.UnitTypes 
    (
    Id int NOT NULL, 
    Notes varchar(80) 
    ) 
GO 
CREATE TABLE dbo.Tracking 
    (
    Id int NOT NULL IDENTITY (1, 1), 
    BoxId int NOT NULL, 
    Revision int NOT NULL, 
    UnitValue int NULL, 
    UnitTypeId int NULL, 
    SetNumber int NULL 
    ) 
GO 
ALTER TABLE dbo.Tracking ADD CONSTRAINT 
    PK_Tracking PRIMARY KEY CLUSTERED 
    (
    Id 
    ) 
GO 
Insert Into dbo.UnitTypes (Id, Notes) Values (1, 'X Coord'), 
              (2, 'Y Coord'), 
              (3, 'Weight'), 
              (4, 'Length') 
Go 
Insert Into dbo.Tracking (BoxId, Revision, UnitValue, UnitTypeId, SetNumber) 
       Values (1165, 1, 150, 1, NULL), 
        (1165, 1, 1477, 2, NULL), 
        (1165, 1, 31, 4, NULL), 
        (1166, 1, 425, 1, 1), 
        (1166, 1, 1146, 2, 1), 
        (1166, 1, 438, 1, NULL), 
        (1166, 1, 1163, 2, NULL), 
        (1167, 1, 560, 1, NULL), 
        (1167, 1, 909, 2, NULL), 
        (1167, 1, 12763, 3, NULL), 
        (1168, 1, 21, 1, NULL), 
        (1168, 1, 13109, 3, NULL) 

理想的結果將是：

Id BoxId Revision UnitValue UnitTypeId SetNumber 
1 1165   1   150   1   1 
2 1165   1   1477   2   1 
3 1165   1   31   4   1 
4 1166   1   425   1   1 
5 1166   1   1146   2   1 
6 1166   1   438   1  NULL <--NULL Because there is already an existing Set 
7 1166   1   1163   2  NULL <--NULL Because there is already an existing Set 
8 1167   1   560   1   1 
9 1167   1   909   2   1 
10 1167   1  12763   3   1 
11 1168   1   21   1  NULL <--NULL Because there is not exactly one UnitTypeId of 1 and exactly one UnitTypeId of 2 for this BoxId\Revision combination. 
12 1168   1  13109   3  NULL <--NULL Because there is not exactly one UnitTypeId of 1 and exactly one UnitTypeId of 2 for this BoxId\Revision combination. 

編輯： 問題是，如何使用純TSQL更新SetNumber，給定上面的約束條件？

Answer 1

如果我正確理解你的問題，你可以用它要求所有條件都滿足的子查詢做到這一點：

update t1 
set  SetNumber = 1 
from dbo.Tracking t1 
where SetNumber is null 
     and 1 = 
     (
     select case 
       when count(case when t2.UnitTypeId = 1 then 1 end) <> 1 then 0 
       when count(case when t2.UnitTypeId = 2 then 1 end) <> 1 then 0 
       when count(t2.SetNumber) <> 0 then 0 
       else 1 
       end 
     from dbo.Tracking t2 
     where t1.BoxId = t2.BoxId 
       and t1.Revision = t2.Revision 
     ) 

的count(t2.SetNumber)是有點棘手：其中SetNumber不null這隻會計算行。所以這符合不存在與其他組相同的標準(BoxId, Revision)的標準。

Answer 2

試試看，它會返回與您給出的結果相同的結果。語句WITH設置了一個CTE來查詢。 ROW_NUMBER()功能是分區功能，它可以做你想做的事：

;WITH BoxSets AS (
SELECT 
    ID 
    ,BoxId 
    ,Revision 
    ,UnitValue 
    ,UnitTypeId 
    ,CASE WHEN UnitTypeId IN (1,2) THEN 1 ELSE 0 END ValidUnit 
    ,ROW_NUMBER() OVER (PARTITION BY BoxID,UnitTypeID ORDER BY BoxID,UnitTypeID,UnitValue) SetNumber 
FROM Tracking 
) 

SELECT 
    b.ID 
    ,b.BoxId 
    ,b.Revision 
    ,b.UnitValue 
    ,b.UnitTypeId 
    ,CASE ISNULL(b1.ValidUnits,0) WHEN 0 THEN NULL ELSE CASE b.SetNumber WHEN 1 THEN b.SetNumber ELSE NULL END END 
FROM BoxSets AS b 
LEFT JOIN (SELECT 
      BoxID 
      ,SUM(ValidUnit) AS ValidUnits 
      FROM BoxSets 
      GROUP BY BoxId 
      HAVING SUM(ValidUnit) > 1) AS b1 ON b.BoxId = b1.BoxId