Linq:使用2个不同的语句将proc映射到函数 [英] Linq : mapping proc to fuction with 2 different statement

问题描述

我使存储过程有条件地选择数据，但问题是:-

当RequiredIDID = 2(从联接表中选择一些数据，如果不是，我不在else语句中选择它)并且映射到linq函数后，出现此问题

如果我将requirdID = 2传递给函数，则不会发生任何问题，因为在执行过程中执行了第一个选择，但是如果我传递了其他requirdID(例如= 3)，则出现此消息

数据读取器与指定的"RealEstateCenterModel.SearchForRealState_Reader"不兼容.类型成员"FloorTypeCategory"在数据读取器中没有具有相同名称的对应列.

I make stored procedure that select data with condition but the problem is :-

when RequiredIDID =2 ( Select come with some data from join table and if not I am not select it in else statement ) and after mapping to linq function this problem appears

if I''m pass requirdID = 2 to function no problem occurs coz the first select in proc executed but if i pass other requirdID ( ex. = 3 ) this message appears

The data reader is incompatible with the specified ''RealEstateCenterModel.SearchForRealState_Reader''. A member of the type, ''FloorTypeCategory'', does not have a corresponding column in the data reader with the same name.

USE [RealEstateCenter]
GO
/****** Object:  StoredProcedure [dbo].[TestOptionalParameter]    Script Date: 08/23/2012 07:29:02 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER proc [dbo].[TestOptionalParameter]
@RequiredIDID int =NULL 
as

if @RequiredIDID=2
begin
SELECT     FloorSpace.SpaceFrom, RealEstateCategoryDetails.RequiredCategoryTypeName, FloorType.FloorTypeCategory, FloorType.FloorNotes, 
                      RealEstateTypes.RequiedType
FROM         PersonalRealStateDetails INNER JOIN
                      FloorSpace ON PersonalRealStateDetails.FloorSpaceID = FloorSpace.FloorSpaceID INNER JOIN
                      RealEstateCategoryDetails ON PersonalRealStateDetails.RequiredCategoryTypeID = RealEstateCategoryDetails.RequiredCategoryTypeID INNER JOIN
                      FloorType ON PersonalRealStateDetails.FloorTypeID = FloorType.FloorTypeID INNER JOIN
                      RealEstateTypes ON RealEstateCategoryDetails.RequiredID = RealEstateTypes.RequiredID

end

else
begin
SELECT     FloorSpace.SpaceFrom, RealEstateCategoryDetails.RequiredCategoryTypeName, RealEstateTypes.RequiedType
FROM         PersonalRealStateDetails INNER JOIN
                      FloorSpace ON PersonalRealStateDetails.FloorSpaceID = FloorSpace.FloorSpaceID INNER JOIN
                      RealEstateCategoryDetails ON PersonalRealStateDetails.RequiredCategoryTypeID = RealEstateCategoryDetails.RequiredCategoryTypeID INNER JOIN
                      RealEstateTypes ON RealEstateCategoryDetails.RequiredID = RealEstateTypes.RequiredID
end

推荐答案

我会说引发了错误，因为当@RequiredIDID！= 2时，您生成的查询仅提供3列.C#分析了存储的程序，并且总是期望有5列.

这可以通过在@RequiredIDID不等于2时提供2个额外的列来解决.例如，将代码的ELSE部分更改为:

I would say that the error is raised, because your resulting query supplies only 3 columns when the @RequiredIDID != 2. C# has analyzed the stored procedure and always expects 5 columns.

This could be solved by supplying 2 extra columns when the @RequiredIDID is not equal to 2. For instance change the ELSE part of your code to:

else
begin
SELECT     FloorSpace.SpaceFrom, RealEstateCategoryDetails.RequiredCategoryTypeName, 
NULL as FloorTypeCategory, NULL as FloorNotes,
RealEstateTypes.RequiedType
FROM         PersonalRealStateDetails INNER JOIN
                      FloorSpace ON PersonalRealStateDetails.FloorSpaceID = FloorSpace.FloorSpaceID INNER JOIN
                      RealEstateCategoryDetails ON PersonalRealStateDetails.RequiredCategoryTypeID = RealEstateCategoryDetails.RequiredCategoryTypeID INNER JOIN
                      RealEstateTypes ON RealEstateCategoryDetails.RequiredID = RealEstateTypes.RequiredID
end

这应该使代码正常工作.我希望它能提供理想的结果.

This should make the code work. I hope it give the desired result.

这是两个不同的查询，基于您要传入的参数.您应该执行两个不同的查询，并在其中进行切换基于参数的C#，例如

It''s two different queries, based on a parameter you''re passing in. You should just do two different queries and switch between them in the C# based on the parameter, e.g.

if(RequiredID == 2){
 var answer = select from ... (first query)
} else {
 var answer = select from ... (other query)
}

我猜一个人将不得不返回一个类型列表，该类型是另一个的子类，因为有额外的属性.然后，您必须考虑如何在以后的应用程序中访问这些属性.

I guess one will have to return a list of a type that is a subclass of the other, as there are extra properties. Then you have to think about how you can access those properties later in your application.

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