原文地址：http://blogs.microsoft.co.il/gilf/2010/05/09/how-to-retrieve-stored-procedure-output-parameters-in-entity-framework/
How to Retrieve Stored Procedure Output Parameters in Entity Framework
One question that 
raises from time to
time in EF forums
is how you can
retrieve stored
procedure output
parameters in EF
Function Import.
This post will show you how to do that.
The Stored Procedure
In the example I’m going to use the following stored procedure:
CREATE PROCEDURE dbo.SchoolBudgetForDateRange
@StartDate DATETIME,
@EndDate DATETIME,
@Sum money output
AS
SET NOCOUNT ON;
SELECT @Sum = SUM(Department.Budget)
FROM Department
WHERE StartDate BETWEEN @StartDate AND @EndDate
The stored procedure returns the school budget for a given date.
By of course the stored procedure could return that calculation
without using an output parameter.
Retrieving Stored Procedure Output Parameter
After creating a Function Import (which is explained here) we can
use the SchoolBudgetforDateRange method with the context we have.
In order to get an output parameter you need to supply an ObjectParameter
to the stored procedure call which holds the parameter name and type.
After the execution of the stored procedure you can retrieve the
parameter using the Value property of the ObjectParameter.
The following code shows how to that exactly what I wrote:
static void Main(string[] args)
{
using (SchoolEntities context = new SchoolEntities())
{
var outputParameter = new ObjectParameter(“sum”, typeof(decimal));
context.SchoolBudgetForDateRange(new DateTime(2007, 1, 1),
new DateTime(2008, 1, 1),
outputParameter);
Console.WriteLine(outputParameter.Value);
}
}
Summary
Once you need to retrieve output parameters from EF Function Imports,
you need to supply an ObjectParameter to hold the output. In the post
I showed how to do that.
----------------------------------------
自我测试
ALTER PROC [dbo].[usp_AddTeacherInfo]
@Name NVARCHAR(50),
@Phone NVARCHAR(50),
@Address NVARCHAR(50),
@Age INT,
@Sum UNIQUEIDENTIFIER OUTPUT
AS
BEGIN
SET NOCOUNT ON
DECLARE @TmpID UNIQUEIDENTIFIER
SET @TmpID = NEWID()
INSERT INTO dbo.Teacher
(ID, Name, Phone, Address, Age )
VALUES ( @TmpID,@Name,@Phone,@Address,@Age)
SET @Sum = @TmpID
SET NOCOUNT OFF
END
public void AddTeacherInfo()
{
using (DemoDBEntities entity = new DemoDBEntities())
{
var outputParameter = new ObjectParameter("sum", typeof(Guid));
var dd = entity.usp_AddTeacherInfo("dapeng", "021-99999999", "address222", 86, outputParameter);
}
}