标签：style color 使用 os io strong for art
select中使用case when
linq代码：
Products.Select(P => new
{
ID = P.ProductID,
Name = P.Name,
Color = P.Color,
Price = (P.Color == "Red" ? P.StandardCost : (P.Color == "Black" ? P.StandardCost + 10 : P.ListPrice))
});
sql原型：
SELECT ProductID, Name, Color,
CASE
WHEN Color = ‘Red‘ THEN StandardCost
WHEN Color = ‘Black‘ THEN StandardCost + 10
ELSE ListPrice
END Price
FROM SalesLT.Product
where中使用case when
linq代码：
Products
.Where(P => (P.Color == "Red" ? (P.StandardCost > 100) : (P.Color == "Black" ? P.ListPrice > 100 : P.ListPrice == P.StandardCost)))
.Select(P => new
{
ID = P.ProductID,
Name = P.Name,
Color = P.Color,
StandardCost = P.StandardCost,
ListPrice = P.ListPrice
});
sql原型：
SELECT ProductID, Name, Color, StandardCost, ListPrice
FROM SalesLT.Product
WHERE (
(CASE
WHEN Color = ‘Red‘ THEN
(CASE
WHEN StandardCost > 100 THEN 1
WHEN NOT (StandardCost > 100) THEN 0
ELSE NULL
END)
WHEN Color = ‘Black‘ THEN
(CASE
WHEN ListPrice > 100 THEN 1
WHEN NOT (ListPrice > 100) THEN 0
ELSE NULL
END)
ELSE
(CASE
WHEN ListPrice = StandardCost THEN 1
WHEN NOT (ListPrice = StandardCost) THEN 0
ELSE NULL
END)
END)) = 1
group by中使用case when
linq代码：
Products.GroupBy(P => P.StandardCost > 1000? P.Color : P.SellStartDate.ToString())
sql原型：
-- Region Parameters
DECLARE @p0 Decimal(8,4) = 1000
-- EndRegion
SELECT [t1].[value] AS [Key]
FROM (
SELECT
(CASE
WHEN [t0].[StandardCost] > @p0 THEN CONVERT(NVarChar(MAX),[t0].[Color])
ELSE CONVERT(NVarChar(MAX),[t0].[SellStartDate])
END) AS [value]
FROM [SalesLT].[Product] AS [t0]
) AS [t1]
GROUP BY [t1].[value]
GO
linq中使用case when,布布扣,bubuko.com
linq中使用case when
标签：style color 使用 os io strong for art
原文地址：http://www.cnblogs.com/Mh201454/p/3904097.html
