Question

对于BoxId和Revision的每个唯一组合，单个UnitTypeId为1且单个UnitTypeId为2都具有NULL SetNumber，请指定SetNumber为1。

表格和数据设置：

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)

理想的结果将是：

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.

修改问题是如何在给定上述约束的情况下使用纯TSQL来更新SetNumber？

Answer 1

如果我正确理解了您的问题，您可以使用要求满足所有条件的子查询来执行此操作：

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
        )

count(t2.SetNumber)有点棘手：这只会计算SetNumber不是null的行。因此，这符合不存在具有相同(BoxId, Revision)的其他集合的标准。

Answer 2

试试这个，它会返回你给出的相同结果。 WITH语句设置要查询的CTE。 ROW_NUMBER()函数是执行您想要的分区函数：

;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

根据多列条件在同一个表中创建“集合”

2 个答案: