使用SqlHelper.ExecuteDataSet（）和获取返回值执行SQL Server存储过程

Question

I have an SQL Server Stored Procedure . This procedure have an output parameter. On my C#.NET Appliaction, I execute this procedure via SqlHelper.ExecuteDataSet() and it returns a query result DataSet . How can I get the output parameter from the stored procedure procedure while using SqlHelper.ExecuteDataSet() . Some article said that I need to use SqlHelper.ExecuteNonQuery() but I need the DataSet too.

This is my code:

        public DataSet GetDataPerTable(string spName, string a, string b, out int c)
        {
            try
            {
                c = 0;

                SqlParameter[] spParameter = new SqlParameter[3];

                spParameter[0] = new SqlParameter("@a", SqlDbType.Char, 4);
                spParameter[0].Direction = ParameterDirection.Input;
                spParameter[0].Value = a;

                spParameter[1] = new SqlParameter("@b", SqlDbType.Char, 1);
                spParameter[1].Direction = ParameterDirection.Input;
                spParameter[1].Value = b;

                spParameter[2] = new SqlParameter("@c", SqlDbType.Int);
                spParameter[2].Direction = ParameterDirection.ReturnValue;                
                c = Convert.ToInt32(spParameter[2].Value);

                return SqlHelper.ExecuteDataset(Configuration.MyConnectionString, CommandType.StoredProcedure, spName, spParameter);
            }
            catch (Exception ex)
            {

                throw ex;
            }
        }

My c variable always return 0. Any Idea? Thanks in advance :)

My Procedure is about like this:

CREATE PROCEDURE [dbo].SPR_MyProcedure (@a Char(4), @bChar(1), @c Int Output)  
SELECT * 
FROM MyTable
Set @c = 1

Answer 1

@c isn't the a return value, it's an output parameter

Change

spParameter[2].Direction = ParameterDirection.ReturnValue; 

to

 spParameter[2].Direction = ParameterDirection.Output;

Also, you need to set your c variable after the call to ExecuteDataset eg:

DataSet dataset = SqlHelper.ExecuteDataset(Configuration.MyConnectionString, CommandType.StoredProcedure, spName, spParameter);
c=(int)spParameter[2];
return dataset;     

Answer 2

You have to use ParameterDirection.Output for parameter c . see Get output parameter value in ADO.NET

ParameterDirection.ReturnValue is a return value of the whole stored procedure, 0 by default or a value specified in RETURN statement.

Answer 3

SqlHelper.ExecuteDataSet doesnt return output parameter. see this link

http://www.mediachase.com/documentation/fileuploader/Api/Mediachase.FileUploader.SqlHelper.ExecuteDataset_overload_5.html

for output parameter in every example they r using ExecuteNonQuery see these aticles for output prameter

http://forums.asp.net/t/360456.aspx/1

http://www.codeproject.com/Articles/15666/Data-Access-Application-Block-NET-2-0-Get-Return-V

i hope it can help u