SQL SERVER 2008的转置函数PIVOT

PIVOT函数用于转置数据，即用旋转表的方式把行换成列。PIVOT可以将表中的列换成行

如下面的例子：

CREATE TABLE Sales.SalesByMonth
(
    year char(4),
    month char(3),
    amount MONEY,
    PRIMARY KEY(year,month)
)

INSERT INTO Sales.SalesByMonth(year,month,amount)
values('2007','Jan',789.0000),
      ('2007','Feb',389.0000),
      ('2007','Mar',8867.0000),
      ('2007','Apr',778.0000),
      ('2007','May',78.0000),
      ('2007','Jun',9.0000),
      ('2007','Jul',987.0000),
      ('2007','Aug',866.0000),
      ('2007','Sep',7787.0000),
      ('2007','Oct',85576.0000),
      ('2007','Nov',855.0000),
      ('2007','Dec',5875.0000),
      
      ('2008','Jan',7.0000),
      ('2008','Feb',6868.0000),
      ('2008','Mar',688.0000),
      ('2008','Apr',9897.0000)
      
SELECT YEAR,
       SUM(case when month='Jan' then amount else 0 end) as 'Jan',
       SUM(case when month='Feb' then amount else 0 end) as 'Feb',
       SUM(case when month='Mar' then amount else 0 end) as 'Mar',
       SUM(case when month='Apr' then amount else 0 end) as 'Apr',
       SUM(case when month='May' then amount else 0 end) as 'May',
       SUM(case when month='Jun' then amount else 0 end) as 'Jun',
       SUM(case when month='Jul' then amount else 0 end) as 'Jul',
       SUM(case when month='Aug' then amount else 0 end) as 'Aug',
       SUM(case when month='Sep' then amount else 0 end) as 'Sep',
       SUM(case when month='Oct' then amount else 0 end) as 'Oct',
       SUM(case when month='Nov' then amount else 0 end) as 'Nov',
       SUM(case when month='Dec' then amount else 0 end) as 'Dec'
FROM Sales.SalesByMonth 
group by year     

select YEAR,[Jan],[Feb],[Mar],[Apr],[May],[Jun],
            [Jul],[Aug],[Sep],[Oct],[Nov],[Dec]
FROM 
    (Select YEAR,amount,month from Sales.SalesByMonth) as SalesByMonth 
    pivot (sum(amount) for month in 
            (
                [Jan],[Feb],[Mar],[Apr],[May],[Jun],
                [Jul],[Aug],[Sep],[Oct],[Nov],[Dec]
            )) as ourPivot
order by year

显示结果为：

如果去掉year选项，语句改为：

select [Jan],[Feb],[Mar],[Apr],[May],[Jun],
            [Jul],[Aug],[Sep],[Oct],[Nov],[Dec]
FROM 
    (Select amount,month from Sales.SalesByMonth) as SalesByMonth 
    pivot (sum(amount) for month in 
            (
                [Jan],[Feb],[Mar],[Apr],[May],[Jun],
                [Jul],[Aug],[Sep],[Oct],[Nov],[Dec]
            )) as ourPivot

则显示结果：