0

我有以下我一直在构建的 SQL 语句，它根据“产品数据”表中值的顺序返回一系列值

例如，产品 TV 具有屏幕尺寸，我们希望根据用户配置查询屏幕在指定范围内的电视。所以他们可能会说，给我 42 英寸两侧 3 种尺寸的替代电视。

此查询仅基于指定产品执行此操作：

DECLARE @ProductType INT = (
                             SELECT p.prod_ptype_id
                                FROM product p
                                WHERE p.prod_id = @ProductId
                           )
DECLARE @AttributeId INT = (
                             SELECT at.aptype_attr_id
                                FROM Attribute_ProductType at
                                INNER JOIN Attribute a
                                    ON a.attr_id = at.aptype_attr_id
                                WHERE ISNULL(a.ReplacementTolerant, 0) = 1
                                    AND at.aptype_ptype_id = @ProductType
                           )
DECLARE @ToleranceRange INT = (
                                SELECT a.ToleranceRange
                                    FROM Attribute_ProductType at
                                    INNER JOIN Attribute a
                                        ON a.attr_id = at.aptype_attr_id
                                    WHERE ISNULL(a.ReplacementTolerant, 0) = 1
                                        AND at.aptype_ptype_id = @ProductType
                              )
DECLARE @AttributeValueIndex INT = (
                                     SELECT DISTINCT ( av.attrval_index )
                                        FROM Product_Attribute pa
                                        INNER JOIN AttributeValue av
                                            ON av.attrval_attr_id = pa.pattr_attr_id
                                        WHERE av.attrval_id = (
                                                                SELECT pattr_attrval_id
                                                                    FROM product_attribute pa3
                                                                    WHERE pa3.pattr_prod_id = @ProductId
                                                                        AND pa3.pattr_attr_id = @AttributeId
                                                              )
                                   );


WITH    ProductTypeAttributes
          AS (
               SELECT DISTINCT attrval_val
                   ,attrval_index
                   ,ROW_NUMBER() OVER ( ORDER BY attrval_index ) AS RowNumber
                FROM Product_Attribute pa
                INNER JOIN AttributeValue av
                    ON av.attrval_id = pa.pattr_attrval_id
                INNER JOIN Product p
                    ON p.prod_id = pa.pattr_prod_id
                WHERE pa.pattr_attr_id = @AttributeId
                    AND p.prod_ptype_id = @ProductType
                GROUP BY attrval_val
                   ,attrval_index
             )
    SELECT *
        FROM ProductTypeAttributes
        WHERE RowNumber >= (
                             (SELECT DISTINCT ( RowNumber )
                                FROM ProductTypeAttributes pta2
                                WHERE attrval_index = @AttributeValueIndex)
                           ) - @ToleranceRange
            AND ( RowNumber <= (
                                 SELECT DISTINCT ( RowNumber )
                                    FROM ProductTypeAttributes pta3
                                    WHERE attrval_index = @AttributeValueIndex
                               ) + @ToleranceRange )

这一切都很好，并且完全按照我的需要工作，尽管它可能需要一些优化，但现在我只想能够将它作为 POC 固定在需要的地方。

显而易见的选择是让它成为一个表函数——但是当我有这些“声明”语句时，我不知道要应用什么语法。

我查看了 MSDN 和示例，这些示例显示了与我认为我需要实现的类似示例，但我无法理解如何以这种方式将声明语句与表函数结合使用。

任何人都可以对此有所了解吗？

谢谢！

4

2 回答 2

0

我无法用我愿意投入的时间快速将整个查询转换为内联函数，尤其是在不了解表中的内容以及它们之间的关系的情况下。但是，我相信我下面的内容至少会用更可重用的东西取代你的前 4 个选择。我相信使用相同的概念，您也可以将查询的其余部分合并到这个函数中——或者可能是第二个函数以实现更高的模块化。在尝试转换之前，您最好先进行优化。

CREATE FUNCTION  GetProductInfo
(
    @ProductID int
)

RETURNS TABLE
AS
    RETURN
        SELECT
            p.prod_ptype_id AS ProductType,
            at.aptype_attr_id AS AttributeId,
            a.ToleranceRange AS ToleranceRange
            av.attrval_index AS AttributeValueIndex
        FROM        product p
        INNER JOIN  Attribute_ProductType at
        ON          at.aptype_ptype_id = p.prod_ptype_id
        INNER JOIN  Attribute a
        ON          a.attr_id = at.aptype_attr_id
        AND         a.ReplacementTolerant = 1
        -- This next section got a little confusing for me. Knowing more about what is in the various tables would help me figure out which tables
        --      might produce duplicate rows requiring the CROSS APPLY TOP 1 construct and which could be simple JOINs.
        -- Also, you are using Product_Attribute twice in the same query for @AttributeValueIndex in a confusing (to me) way, so I attempted to simplify here.
        CROSS APPLY (
                        SELECT
                            TOP 1 *
                        FROM        product_attribute pa_all
                        WHERE       pa_all.pattr_prod_id = p.prod_ptype_id
                        AND         pa_all.pattr_attr_id = at.aptype_attr_id
                    ) AS pa
        INNER JOIN  AttributeValue av
        ON          av.attrval_attr_id = pa.pattr_attr_id
        AND         av.attrval_id = pa.pattr_attrval_id
        WHERE       p.prod_id = @ProductId;

GO

DECLARE
    @ProductType INT
    @AttributeId INT
    @ToleranceRange INT,
    @AttributeValueIndex INT;
SELECT
    @ProductType = ProductType,
    @AttributeId = AttributeId,
    @ToleranceRange = ToleranceRange,
    @AttributeValueIndex = AttributeValueIndex
FROM        GetProductInfo
            (
                @ProductID
            );
于 2014-03-13T16:32:49.213 回答
0

尽管我之前的评论，而不是内联，我最终使用了一个多语句表函数：

CREATE FUNCTION GetAttributeToleranceRange
(   
    @ProductId int
)
RETURNS @ProductTypeToleranceRange TABLE
(
    prod_type int,
    attr_id int,
    attrval_val nvarchar(max),
    attrval_index int, 
    RowNumber int
)
AS BEGIN

    DECLARE @ProductTypeAttributesTable TABLE
    (
        attrval_val nvarchar(max),
        attrval_index int, 
        RowNumber int
    )

    declare @ProductType int
    declare @AttributeId int 
    declare @ToleranceRange int 
    declare @AttributeValueIndex int 

    SELECT @ProductType = (SELECT p.prod_ptype_id FROM product p WHERE p.prod_id=@ProductId)

    SELECT @AttributeId = (SELECT at.aptype_attr_id FROM Attribute_ProductType at INNER JOIN Attribute a ON a.attr_id = at.aptype_attr_id WHERE ISNULL(a.ReplacementTolerant,0)=1 AND at.aptype_ptype_id = @ProductType)
    SELECT @ToleranceRange = (SELECT a.ToleranceRange FROM Attribute_ProductType at INNER JOIN Attribute a ON a.attr_id = at.aptype_attr_id WHERE ISNULL(a.ReplacementTolerant,0)=1 AND at.aptype_ptype_id = @ProductType)
    SELECT @AttributeValueIndex = (SELECT DISTINCT(av.attrval_index) FROM Product_Attribute pa INNER JOIN AttributeValue av ON av.attrval_attr_id=pa.pattr_attr_id WHERE av.attrval_id = (SELECT pattr_attrval_id FROM product_attribute pa3 WHERE pa3.pattr_prod_id=@ProductId and pa3.pattr_attr_id=@AttributeId));

    INSERT @ProductTypeAttributesTable SELECT DISTINCT attrval_val, attrval_index, ROW_NUMBER() OVER (ORDER BY attrval_index) As RowNumber
    FROM Product_Attribute pa 
    INNER JOIN AttributeValue av ON av.attrval_id = pa.pattr_attrval_id
    INNER JOIN Product p ON p.prod_id = pa.pattr_prod_id
    WHERE pa.pattr_attr_id = @AttributeId AND p.prod_ptype_id = @ProductType
    GROUP BY attrval_val, attrval_index;

    INSERT @ProductTypeToleranceRange SELECT @ProductType, @AttributeId, * FROM @ProductTypeAttributesTable WHERE RowNumber >= ((SELECT DISTINCT(RowNumber) FROM @ProductTypeAttributesTable pta2 WHERE attrval_index=@AttributeValueIndex)) - @ToleranceRange AND (RowNumber <= (SELECT DISTINCT(RowNumber) FROM @ProductTypeAttributesTable pta3 WHERE attrval_index=@AttributeValueIndex) + @ToleranceRange)
    RETURN
END

同样，它将受益于一些优化，但它确实为我提供了使用单个参数所需的东西，同时可以在我需要的地方使用。

于 2014-03-17T12:15:36.633 回答