1

我们有一个简单的 LOB 应用程序：

  • 从EF中提取数据
  • 使用WCF 数据服务通过网络提供数据
  • 在 Telerik 的RadGridView上呈现该数据

这在默认情况下非常有效，因为用户可以使用内置的 Telerik 过滤器控件来过滤数据，该控件提供了他们想要的所有选项。

当使用“包含”运算符时，重新构造从 WCF 数据服务发送的查询时会出现问题：

  • WCF 数据服务添加了一堆“IIF”lambda 表达式，
  • 然后 EF 扩展为 T-SQL CASE 语句

这需要一个如下所示的查询：

SELECT TOP (25) 
[Project1].[TaskID] AS [TaskID], 
[Project1].[ProductSubmissionID] AS [ProductSubmissionID], 
...
FROM ( SELECT 
    [Extent1].[TaskID] AS [TaskID], 
    [Extent1].[ProductSubmissionID] AS [ProductSubmissionID], 
    ...
FROM     [dbo].[Task] AS [Extent1]
    LEFT OUTER JOIN [dbo].[OperationDataProduct] AS [Extent2] ON [Extent1].[ProductID] = [Extent2].[ProductID]
    LEFT OUTER JOIN [dbo].[vProductOwnership] AS [Extent3] ON [Extent1].[ProductID] = [Extent3].[ProductID]
    LEFT OUTER JOIN [dbo].[User] AS [Extent4] ON [Extent2].[ChannelManagerID] = [Extent4].[UserID]
    LEFT OUTER JOIN [dbo].[User] AS [Extent5] ON [Extent2].[ProductOwnerID] = [Extent5].[UserID]
    WHERE [Extent1].Type IN ('Content','Concept','Financial') AND [Extent1].MarketplaceName LIKE '%prod%'

变成一个看起来像这样的：

SELECT TOP (25) 
[Project1].[TaskID] AS [TaskID], 
[Project1].[ProductSubmissionID] AS [ProductSubmissionID], 
...
FROM ( SELECT 
    [Extent1].[TaskID] AS [TaskID], 
    [Extent1].[ProductSubmissionID] AS [ProductSubmissionID], 
    ...
FROM     [dbo].[Task] AS [Extent1]
    LEFT OUTER JOIN [dbo].[OperationDataProduct] AS [Extent2] ON [Extent1].[ProductID] = [Extent2].[ProductID]
    LEFT OUTER JOIN [dbo].[vProductOwnership] AS [Extent3] ON [Extent1].[ProductID] = [Extent3].[ProductID]
    LEFT OUTER JOIN [dbo].[User] AS [Extent4] ON [Extent2].[ChannelManagerID] = [Extent4].[UserID]
    LEFT OUTER JOIN [dbo].[User] AS [Extent5] ON [Extent2].[ProductOwnerID] = [Extent5].[UserID]
    WHERE (CASE WHEN (CASE WHEN (((CASE WHEN (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END IS NULL) THEN CAST(NULL AS bit) WHEN (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END LIKE N'%prod%') THEN cast(1 as bit) WHEN ( NOT (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END LIKE N'%prod%')) THEN cast(0 as bit) END) = 1) AND ([Extent1].[SubmissionOrTaskType] IN (N'Content',N'Concept',N'Financial'))) THEN cast(1 as bit) WHEN ( NOT (((CASE WHEN (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END IS NULL) THEN CAST(NULL AS bit) WHEN (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END LIKE N'%prod%') THEN cast(1 as bit) WHEN ( NOT (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END LIKE N'%prod%')) THEN cast(0 as bit) END) = 1) AND ([Extent1].[SubmissionOrTaskType] IN (N'Content',N'Concept',N'Financial')))) THEN cast(0 as bit) END IS NULL) THEN cast(0 as bit) WHEN (((CASE WHEN (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END IS NULL) THEN CAST(NULL AS bit) WHEN (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END LIKE N'%prod%') THEN cast(1 as bit) WHEN ( NOT (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END LIKE N'%prod%')) THEN cast(0 as bit) END) = 1) AND ([Extent1].[SubmissionOrTaskType] IN (N'Content',N'Concept',N'Financial'))) THEN cast(1 as bit) WHEN ( NOT (((CASE WHEN (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END IS NULL) THEN CAST(NULL AS bit) WHEN (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END LIKE N'%prod%') THEN cast(1 as bit) WHEN ( NOT (CASE WHEN ([Extent1].[MarketplaceName] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE LOWER([Extent1].[MarketplaceName]) END LIKE N'%prod%')) THEN cast(0 as bit) END) = 1) AND ([Extent1].[SubmissionOrTaskType] IN (N'Content',N'Concept',N'Financial')))) THEN cast(0 as bit) END) = 1
)  AS [Project1]
ORDER BY [Project1].[TaskID] ASC

我的问题是：以前有没有人遇到过这个问题，是否有低成本的解决方案？

我可以看到将 EF QueryProvider 重写为一种解决方案，但它的成本并不低。

TIA

4

1 回答 1

2

我们最终编写了一个 QueryProvider 来解决这个问题。它最终的成本比最初预期的要低，但仍然增加了一些不必要的复杂性。IQToolkit 有一些很好的例子来说明如何开始。

于 2011-12-16T22:26:26.573 回答