5

我正在尝试解决以下问题。

我觉得这是可能的，但我似乎无法得到它。

这是场景：

Table 1 (Assets)
1 Asset-A
2 Asset-B
3 Asset-C
4 Asset-D

Table 2 (Attributes)
1 Asset-A Red
2 Asset-A Hard
3 Asset-B Red
4 Asset-B Hard
5 Asset-B Heavy
6 Asset-C Blue
7 Asset-C Hard

如果我正在寻找与 Asset-A 具有相同属性的东西，那么它应该识别 Asset-B，因为 Asset-B 具有与 Asset-A 相同的属性（它应该丢弃重，因为 Asset-A 没有指定任何东西不同或相似）。另外，如果我只想要常见的资产 A 和资产 B 的属性，我将如何获得呢？

看起来很简单，但我无法确定它...

我使用的实际表几乎完全是 Table2，只是 AssetId 和 AttributeId 的关联，因此：PK：Id
int：AssetId
int：AttributeId

我只包含资产表的想法以简化问题。

4

9 回答 9

4 
SELECT  ato.id, ato.value
FROM    (
        SELECT  id
        FROM    assets a
        WHERE   NOT EXISTS
                (
                SELECT  NULL
                FROM    attributes ata
                LEFT  JOIN
                        attributes ato
                ON      ato.id = ata.id
                        AND ato.value = ata.value
                WHERE   ata.id = 1
                        AND ato.id IS NULL
                )
        ) ao
JOIN    attributes ato
ON      ato.id = ao.id
JOIN    attributes ata
ON      ata.id = 1
        AND ata.value = ato.value

，或在SQL Server 2005（带有要检查的样本数据）：

WITH    assets AS 
        (
        SELECT 1 AS id, 'A' AS name
        UNION ALL
        SELECT 2 AS id, 'B' AS name
        UNION ALL
        SELECT 3 AS id, 'C' AS name
        UNION ALL
        SELECT 4 AS id, 'D' AS name
        ),
        attributes AS
        (
        SELECT 1 AS id, 'Red' AS value
        UNION ALL
        SELECT 1 AS id, 'Hard' AS value
        UNION ALL
        SELECT 2 AS id, 'Red' AS value
        UNION ALL
        SELECT 2 AS id, 'Hard' AS value
        UNION ALL
        SELECT 2 AS id, 'Heavy' AS value
        UNION ALL
        SELECT 3 AS id, 'Blue' AS value
        UNION ALL
        SELECT 3 AS id, 'Hard' AS value
        )
SELECT  ato.id, ato.value
FROM    (
        SELECT  id
        FROM    assets a
        WHERE   a.id <> 1
                AND NOT EXISTS
                (
                SELECT  ata.value
                FROM    attributes ata
                WHERE   ata.id = 1
                EXCEPT
                SELECT  ato.value
                FROM    attributes ato
                WHERE   ato.id = a.id
                )
        ) ao
JOIN    attributes ato
ON      ato.id = ao.id
JOIN    attributes ata
ON      ata.id = 1
        AND ata.value = ato.value
于 2009-07-21T15:30:13.370 回答
0

我不完全理解您问题的第一部分，即根据资产的属性识别资产。

对列名进行一些假设，以下查询将产生 Asset-A 和 Asset-B 之间的公共属性：

SELECT [Table 2].Name
FROM [Table 2]
JOIN [Table 1] a ON a.ID = [Table 2].AssetID AND a.Name = 'Asset-A'
JOIN [Table 1] b ON b.ID = [Table 2].AssetID AND b.Name = 'Asset-B'
GROUP BY [Table 2].Name
于 2009-07-21T15:32:31.883 回答
0 
 Select * From Assets A
    Where Exists 
      (Select * From Assets
       Where AssetId <> A.AssetID
          And (Select Count(*)
               From Attributes At1 Join Attributes At2
                  On At1.AssetId <> At2.AssetId
                      And At1.attribute <> At2.Attribute
               Where At1.AssetId = A.AssetId Asset) = 0 )
    And AssetId = 'Asset-A'
于 2009-07-21T15:40:42.163 回答
0 
select at2.asset, count(*)
from       attribute at1
inner join attribute at2 on at1.value = at2.value
where at1.asset =  "Asset-A"
and   at2.asset != "Asset-A"
group by at2.asset
having count(*) = (select count(*) from attribute where asset = "Asset-A");
于 2009-07-21T15:56:58.247 回答
0

查找具有“A”所有属性（但也可能具有其他属性）的所有资产：

SELECT Other.ID
FROM Assets Other
WHERE
  Other.AssetID <> 'Asset-A'   -- do not return Asset A as a match to itself
  AND NOT EXISTS (SELECT NULL FROM Attributes AttA WHERE
    AttA.AssetID='Asset-A' 
    AND NOT EXISTS (SELECT NULL FROM Attributes AttOther WHERE
      AttOther.AssetID=Other.ID AND AttOther.AttributeID = AttA.AttributeID
      )
    )

即，“找到没有 A 的属性且不是该资产的属性的任何资产”。

查找与“A”具有完全相同属性的所有资产：

SELECT Other.ID
FROM Assets Other
WHERE
  Other.AssetID <> 'Asset-A'   -- do not return Asset A as a match to itself
  AND NOT EXISTS (SELECT NULL FROM Attributes AttA WHERE
    AttA.AssetID='Asset-A' 
    AND NOT EXISTS (SELECT NULL FROM Attributes AttOther WHERE
      AttOther.AssetID=Other.ID 
      AND AttOther.AttributeID = AttA.AttributeID
      )
    ) 
  AND NOT EXISTS (SELECT NULL FROM Attributes AttaOther WHERE
    AttaOther.AssetID=Other.ID 
    AND NOT EXISTS (SELECT NULL FROM Attributes AttaA WHERE
      AttaA.AssetID='Asset-A' 
      AND AttaA.AttributeID = AttaOther.AttributeID
      )
   )

即，“找到不存在A的属性但不是该资产的属性的任何资产，以及不存在该资产的不也是A的属性的属性的任何资产”。

于 2009-07-21T17:38:09.120 回答
0

此解决方案按规定工作，感谢您的输入。

WITH Atts AS 
(
    SELECT
    DISTINCT
        at1.[Attribute]
    FROM
        Attribute at1
    WHERE
        at1.[Asset] = 'Asset-A'
)

SELECT 
    DISTINCT
    Asset,
    (
        SELECT 
            COUNT(ta2.[Attribute]) 
        FROM 
            Attribute ta2 
        INNER JOIN
            Atts b 
            ON
                b.[Attribute] = ta2.[attribute]
        WHERE 
            ta2.[Asset] = ta.Asset
    ) 
    AS [Count]
FROM 
    Atts a
INNER JOIN
    Attribute ta
    ON
    a.[Attribute] = ta.[Attribute]
于 2009-07-21T18:47:25.190 回答
0

查找所有与资产-a 具有相同属性的资产：

select att2.Asset from attribute att1
inner join attribute att2 on att2.Attribute = att1.Attribute and att1.Asset <> att2.Asset
where att1.Asset = 'Asset-A'
group by att2.Asset, att1.Asset
having COUNT(*) = (select COUNT(*) from attribute where Asset=att1.Asset)
于 2009-07-21T19:29:11.610 回答
0

我想也许我可以用 LINQ 做到这一点，然后用我的方式向后工作：

var result = from productsNotA in DevProducts
             where  productsNotA.Product != "A" && 
            (
                from productsA in DevProducts
                where productsA.Product == "A"
                select productsA.Attribute
            ).Except
            (
                from productOther in DevProducts
                where productOther.Product == productsNotA.Product
                select productOther.Attribute
            ).Single() == null
            select new {productsNotA.Product};

result.Distinct()

我认为使用 LinqPad 将其转换回 SQL 会产生一个漂亮的 SQL 查询。然而它没有:)。DevProducts 是我的测试表，其中包含 Product 和 Attribute 列。我想无论如何我都会发布 LINQ 查询，这可能对正在使用 LINQ 的人有用。

如果您可以优化上面的 LINQ 查询，请告诉我（它可能会产生更好的 SQL ;)）

于 2009-07-22T08:52:17.407 回答
0

我正在使用以下 DDL

CREATE TABLE Attributes (
    Asset      VARCHAR(100)
    , Name     VARCHAR(100)
    , UNIQUE(Asset, Name)
    )

第二个问题很简单

SELECT   Name
FROM     Attributes
WHERE    Name IN (SELECT Name FROM Attributes WHERE Asset = 'A')
         AND Asset = 'B'

第一个问题并不难

SELECT   Asset
FROM     Attributes
WHERE    Name IN (SELECT Name FROM Attributes WHERE Asset = 'A')
GROUP BY Asset
HAVING   COUNT(*) = (SELECT COUNT(*) FROM FROM Attributes WHERE Asset = 'A')

编辑：

为简洁起见，我省略AND Asset != 'A'了WHERE第二个片段的子句

于 2009-07-22T21:16:00.663 回答