交叉连接（枢轴）与含N-N的表值

我有3个表：交叉连接（枢轴）与含N-N的表值

TABLE MyColumn (
    ColumnId INT NOT NULL, 
    Label VARCHAR(80) NOT NULL, 
    PRIMARY KEY (ColumnId) 
) 

TABLE MyPeriod (
    PeriodId CHAR(6) NOT NULL, -- format yyyyMM 
    Label VARCHAR(80) NOT NULL, 
    PRIMARY KEY (PeriodId) 
) 

TABLE MyValue (
    ColumnId INT NOT NULL, 
    PeriodId CHAR(6) NOT NULL, 
    Amount DECIMAL(8, 4) NOT NULL, 
    PRIMARY KEY (ColumnId, PeriodId), 
    FOREIGN KEY (ColumnId) REFERENCES MyColumn(ColumnId), 
    FOREIGN KEY (PeriodId) REFERENCES MyPeriod(PeriodId) 
)

提供了一种真正的值时仅创建myvalue的的行。

我希望我的以表格方式的结果，如：

Column | Month 1 | Month 2 | Month 4 | Month 5 | 
Potatoes | 25.00 | 5.00 | 1.60 | NULL | 
Apples | 2.00 | 1.50 | NULL | NULL |

我已经成功地创建了一个交叉联接：

SELECT 
    MyColumn.Label AS [Column], 
    MyPeriod.Label AS [Period], 
    ISNULL(MyValue.Amount, 0) AS [Value] 
FROM 
    MyColumn CROSS JOIN 
    MyPeriod LEFT OUTER JOIN 
    MyValue ON (MyValue.ColumnId = MyColumn.ColumnId AND MyValue.PeriodId = MyPeriod.PeriodId)

或者，在LINQ：

from p in MyPeriods 
from c in MyColumns 
join v in MyValues on new { c.ColumnId, p.PeriodId } equals new { v.ColumnId, v.PeriodId } into values 
from nv in values.DefaultIfEmpty() 
select new { 
    Column = c.Label, 
    Period = p.Label, 
    Value = nv.Amount 
}

并看到如何在linq中创建数据透视表（here或here）：

（假设MyDatas是与以前的查询结果的视图）：

from c in MyDatas 
group c by c.Column into line 
select new 
{ 
    Column = line.Key, 
    Month1 = line.Where(l => l.Period == "Month 1").Sum(l => l.Value), 
    Month2 = line.Where(l => l.Period == "Month 2").Sum(l => l.Value), 
    Month3 = line.Where(l => l.Period == "Month 3").Sum(l => l.Value), 
    Month4 = line.Where(l => l.Period == "Month 4").Sum(l => l.Value) 
}

但我想找到一种方法来创建一个结果，如果可能的话，MONTH1，...特性的动态。

注：

from c in MyDatas 
group c by c.Column into line 
select new 
{ 
    Column = line.Key, 
    Months = 
     from l in line 
     group l by l.Period into period 
     select new 
     { 
      Period = period.Key, 
      Amount = period.Sum(l => l.Value) 
     } 
}

来源

2008-12-16 tbolon