如何使用Nettiers从存储的Proc获得标量值

Question

我有一个非常简单的存储过程，看起来像这样：

CREATE PROCEDURE _Visitor_GetVisitorIDByVisitorGUID
(
 @VisitorGUID AS UNIQUEIDENTIFIER
)

AS

DECLARE @VisitorID AS bigint

SELECT @VisitorID = VisitorID FROM dbo.Visitor WHERE VisitorGUID = @VisitorGUID

--Here's what I've tried 
RETURN @VisitorID 'Returns an IDataReader
SELECT @VisitorID 'Returns an IDataReader
--I've also set it up with a single output
--parameter, but that means I need to pass
--the long in by ref and that's hideous to me

我试图让Nettiers生成具有此签名的方法：

public long VisitorService.GetVisitorIDByVisitorGUID(GUID visitorGUID);

基本上，我希望Nettiers致电ExecutesCalar而不是ExecuteReader。我究竟做错了什么？

Answer 1

为什么不使用自定义数据访问功能使用ExecuteScalar调用您存储的PROC？ （（http://nettiers.com/datalayer.ashx#read_methods:_4)

var vistorId = (long)DataRepository.Provider.ExecuteScalar(CommandType.StoredProcedure, "_Visitor_GetVisitorIDByVisitorGUID");

存储的Proc的主体应该看起来像：

Select VisitorID 
FROM dbo.Visitor 
WHERE VisitorGUID = @VisitorGUID

Return

或者

Declare @VisitorId bigint
Set @VisitorId = (
                Select VisitorId
                From dbo.Visitor
                Where VisitorGuid = @VisitorGUID
                )

Select @VisitorId

Return

Answer 2

对于那些想要以编程方式执行此操作的人，上面的示例将不起作用，因为没有任何方法可以使用该方法的任何替代来传递必要的参数值。

var vistorId = (long)DataRepository.Provider.ExecuteScalar(CommandType.StoredProcedure, "_Visitor_GetVisitorIDByVisitorGUID");

我发现完成此操作的唯一方法是将DBCommand作为唯一参数传递给ExecutesCalar方法：

int myReturnID = 0;
using (SqlCommand cmd = new SqlCommand()) {
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.CommandText = "sp_MyStoredProcedure";
    cmd.Parameters.Add(new SqlParameter("MyParameter", myParameter));
    myReturnID = (Int32)DataRepository.Provider.ExecuteScalar(cmd);
}