sql-server - 在 sqlserver 2008 中检索行作为列

Question

我有一张桌子距离表

它有类似的列

Slno    From    To  Dist
-----------------------------
1   Vskp           Hyd  100 
2   Hyd        Chennai  200 
3   Chennai        Vskp 458

现在我希望数据显示为

       VSKP     HYD     CHENNAI 

VSKP    0km     100km   458km   

HYD     100km     0km   200km

CHANNAI  458km  200km     0km

我试过查询

SELECT *
FROM (  SELECT slno, fromcity ,tocity
        FROM DistanceTable ) AS ET
PIVOT(MIN(slno) FOR fromcity  IN (tocity) AS PT

链接到 .txt 文件中的问题

Answer 1

尝试这个 ：

SELECT fromcity
      ,[Vskp]=isnull([Vskp],0)
      ,[Hyd]=isnull([Hyd],0)
      ,[Chennai]=isnull([Chennai],0)
FROM (  SELECT  fromcity ,tocity,Dist
        FROM DistanceTable
        union

        SELECT  tocity,fromcity ,Dist
        FROM DistanceTable

     ) AS ET
PIVOT
(max(dist) FOR tocity  IN ([Vskp],[Hyd],[Chennai])
) AS PT 

SQL 小提琴

更新： 对可变数量的城市使用动态 SQL，如下所示：

DECLARE
    @cols VARCHAR(MAX),
    @IsNullCols VARCHAR(MAX),
    @query VARCHAR(MAX)


SELECT
    @cols = STUFF((
            SELECT DISTINCT ', [' + tocity + ']'
            FROM (SELECT  tocity FROM DistanceTable
                    union 

                    SELECT  fromcity FROM DistanceTable)a  

            FOR XML PATH('')
          ), 1, 2, '');
print @cols;

SELECT
    @IsNullCols = STUFF((
            SELECT DISTINCT ', ['+tocity+']=IsNull([' + tocity + '],0)'
            FROM (SELECT  tocity FROM DistanceTable
                    union 

                    SELECT  fromcity FROM DistanceTable)a 

            FOR XML PATH('')
          ), 1, 2, '');

print @IsNullCols;          

set @query = 'SELECT fromcity
      ,'+ @IsNullCols +'
FROM (
        SELECT  fromcity ,tocity,Dist
        FROM DistanceTable
        union 

        SELECT  tocity,fromcity ,Dist
        FROM DistanceTable

     ) AS ET
PIVOT
(max(dist) FOR tocity  IN ('+@cols+')
) AS PT '

exec(@query)

Answer 2

这是一个解决方案（但没有支点）：

SELECT 
  fromcity as ' '
  ,ISNULL((SELECT SUM(dist) FROM DistanceTable d2 WHERE (d2.tocity = 'VSKP' AND d2.fromcity = d.fromcity) OR (d2.tocity = d.fromcity AND d2.fromcity = 'VSKP')), 0) as 'VSKP'
  ,ISNULL((SELECT SUM(dist) FROM DistanceTable d2 WHERE (d2.tocity = 'HYD' AND d2.fromcity = d.fromcity) OR (d2.tocity = d.fromcity AND d2.fromcity = 'HYD')), 0) as 'HYD'
  ,ISNULL((SELECT SUM(dist) FROM DistanceTable d2 WHERE (d2.tocity = 'CHENNAI' AND d2.fromcity = d.fromcity) OR (d2.tocity = d.fromcity AND d2.fromcity = 'CHENNAI')), 0) as 'CHENNAI'
FROM DistanceTable d

SQL小提琴

Answer 3

让我用简单的例子来解释这个问题。使用 AdventureWorks

GO

-- Creating Test Table

CREATE TABLE Product(Cust VARCHAR(25), Product VARCHAR(20), QTY INT)

GO

-- Inserting Data into Table

INSERT INTO Product(Cust, Product, QTY)
VALUES('KATE','VEG',2)

INSERT INTO Product(Cust, Product, QTY)
VALUES('KATE','SODA',6)

INSERT INTO Product(Cust, Product, QTY)
VALUES('KATE','MILK',1)

INSERT INTO Product(Cust, Product, QTY)
VALUES('KATE','BEER',12)

INSERT INTO Product(Cust, Product, QTY)
VALUES('FRED','MILK',3)

INSERT INTO Product(Cust, Product, QTY)
VALUES('FRED','BEER',24)

INSERT INTO Product(Cust, Product, QTY)
VALUES('KATE','VEG',3)

GO

-- Selecting and checking entires in table

SELECT *
FROM Product

GO

-- Pivot Table ordered by PRODUCT

SELECT PRODUCT, FRED, KATE
FROM (
SELECT CUST, PRODUCT, QTY
FROM Product) up
PIVOT (SUM(QTY) FOR CUST IN (FRED, KATE)) AS pvt
ORDER BY PRODUCT

GO

-- Pivot Table ordered by CUST

SELECT CUST, VEG, SODA, MILK, BEER, CHIPS
FROM (
SELECT CUST, PRODUCT, QTY
FROM Product) up
PIVOT (SUM(QTY) FOR PRODUCT IN (VEG, SODA, MILK, BEER, CHIPS)) AS pvt
ORDER BY CUST

GO