使用SQL取消透析多列

Question

需要取消列出选项和选项价格列表的多列。可以使用以下代码创建示例起始数据集：

CREATE TABLE testtable (
ID int,
OptionA nvarchar(25),
OptionACost decimal(16,4), 
OptionB nvarchar(25),
OptionBCost decimal(16,4), 
OptionC nvarchar(25),
OptionCCost decimal(16,4) )

INSERT INTO testtable (ID, OptionA, OptionACost, OptionB, OptionBCost, 
OptionC, OptionCCost) 

VALUES
    ('1', 'Red Paint', '11.98', 'Leather Trim', '20.00', 'Matte Finish', '5.66'),
    ('2', 'Blue Paint', '13.48', 'Suede Trim', '16.00', 'Gloss Finish', '3.82'),
    ('3', 'Black Paint', '10.00', 'Leather Trim', '20.00', 'Matte Finish', '5.66'),
    ('4', 'Red Paint', '11.98', 'No Trim', '0.00', 'Matte Finish', '5.66');

我的理想结果样本数据集是使用以下代码创建的：

CREATE TABLE testtableresult (
ID int,
OptionName nvarchar(25),
OptionCost decimal(16,4))

INSERT INTO testtable2 (ID, OptionName, OptionCost)
VALUES
    ('1', 'Red Paint', '11.98'),
    ('2', 'Blue Paint', '13.48'),
    ('3', 'Black Paint', '10.00'),
    ('4', 'Red Paint', '11.98')
    ('1', 'Leather Trim', '20.00'),
    ('2', 'Suede Trim', '16.00'),
    ('3', 'Leather Trim', '20.00'),
    ('4', 'No Trim', '0.00')
    ('1', 'Matte Finish', '5.66'),
    ('2', 'Suede Trim', '3.88'),
    ('3', 'Matte Finish', '5.66'),
    ('4', 'Matte Finish', '5.66');

帮助表示感谢。

Answer 1

SQL Server有Auth::viaRemember()运算符（即APPLY）可以执行与CROSS APPLY

类似的操作

UNPIVOT

Answer 2

SELECT ID, OptionA AS OptionName, 
           CAST(OptionACost as decimal(10,2)) AS OptionCost 
FROM testtable
UNION ALL
SELECT ID, OptionB AS OptionName, 
           CAST(OptionBCost as decimal(10,2)) AS OptionCost 
FROM testtable
UNION ALL
SELECT ID, OptionC AS OptionName, 
           CAST(OptionCCost as decimal(10,2)) AS OptionCost 
FROM testtable
GO

ID | OptionName   | OptionCost
-: | :----------- | :---------
 1 | Red Paint    | 11.98     
 2 | Blue Paint   | 13.48     
 3 | Black Paint  | 10.00     
 4 | Red Paint    | 11.98     
 1 | Leather Trim | 20.00     
 2 | Suede Trim   | 16.00     
 3 | Leather Trim | 20.00     
 4 | No Trim      | 0.00      
 1 | Matte Finish | 5.66      
 2 | Gloss Finish | 3.82      
 3 | Matte Finish | 5.66      
 4 | Matte Finish | 5.66      

dbfiddle here

Answer 3

除Yogesh's解决方案外，以下是动态创建多个CROSS APPLY

的代码

DEMO

注意 主要假设是测试表中的列称为“Option＆lt;＆gt;” 和“选项＆lt;＆gt;费用”，以便正确创建分组

    SET NOCOUNT ON
    IF OBJECT_ID ('tempdb..#Cols') IS NOT NULL DROP TABLE #Cols
    ;WITH Cols as
    (
        SELECT COLUMN_NAME , FIRST_VALUE(COLUMN_NAME) OVER (ORDER BY ORDINAL_POSITION ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) MainCol
        FROM INFORMATION_SCHEMA.COLUMNS 
        WHERE TABLE_NAME = 'testtable'
    )
    SELECT *
    INTO #Cols
    FROM Cols
    WHERE COLUMN_NAME !=MainCol


    DECLARE @ColsOptions NVARCHAR(MAX)= ''
    DECLARE @Sql NVARCHAR(MAX)= ''
    ;WITH Pvt as 
        (
        SELECT *,
        DENSE_RANK() OVER (PARTITION BY MainCol ORDER BY SUBSTRING(COLUMN_NAME,LEN('Option')+1, 1)) Grp
        FROM #Cols
        )
    , InternalPvt AS 
        (
        SELECT * , ROW_NUMBER () OVER (PARTITION BY Grp ORDER BY Grp) InternalGrp
        FROM Pvt
        )
    , CrossApply as 
    (
     SELECT MAX(MainCol) MainCol,
            MAX(CASE WHEN  InternalGrp = 1 THEN COLUMN_NAME END) [Option],
            MAX(CASE WHEN  InternalGrp = 2 THEN COLUMN_NAME END) OptionCost,
            Grp
     FROM InternalPvt   
     GROUP BY Grp
     )

     SELECT @ColsOptions += '('+MainCol+','+[Option]+','+OptionCost+','+CONVERT(NVARCHAR(10),Grp) +'),'+CHAR(10) 
     FROM CrossApply
     SET @ColsOptions = SUBSTRING(@ColsOptions,0,LEN(@ColsOptions) - 1 )

     SET @sql = 
    'SELECT a.*
     FROM testtable t
     CROSS APPLY (
                VALUES '+@ColsOptions+'
                ) a(Id, Name, Cost, ids)
     ORDER BY a.ids, a.id'

    exec sp_executesql @Sql