Retrieve data from stored procedure which has multiple result sets

String myConnString  = "User ID="username";password="password";Initial Catalog=pubs;Data Source=Server";
SqlConnection myConnection = new SqlConnection(myConnString);
SqlCommand myCommand = new SqlCommand();
SqlDataReader myReader ;

myCommand.CommandType = CommandType.StoredProcedure;
myCommand.Connection = myConnection;
myCommand.CommandText = "MyProc";

try
{
    myConnection.Open();
    myReader = myCommand.ExecuteReader();

    while (myReader.Read())
    {
        //Write logic to process data for the first result.   
        }

    myReader.NextResult();
    while (myReader.Read())
    {
        //Write logic to process data for the second result.
    }
}

While this does not appear to be supported natively in T-SQL, if using a CLR Stored Procedure is an option for you, then you should be able to create a Stored Procedure in your preferred .Net language that uses the SqlDataReader.NextResult() method to advance to the desired result set and then send the SqlDataReader back via the SqlPipe.Send(SqlDataReader) method. You would just need to pass in the SQL to execute and the desired result set as parameters to this proc.

This would allow you to work with the proc as is, without modifying it to send back all or only one result set.

In TSQL land, you're stuck.

Here is a trick (some may call semi-hacky) way that I used one time.

/*  START TSQL CODE */

/*  Stored Procedure Definition */

Use Northwind
GO


IF EXISTS 
    (
    SELECT * FROM INFORMATION_SCHEMA.ROUTINES
    WHERE ROUTINE_TYPE = N'PROCEDURE' and ROUTINE_SCHEMA = N'dbo' and ROUTINE_NAME = N'uspOrderDetailsByCustomerId'  
    )
BEGIN
    DROP PROCEDURE [dbo].[uspOrderDetailsByCustomerId]
END


GO

CREATE Procedure dbo.uspOrderDetailsByCustomerId
(
  @CustomerID nchar(5)
, @ResultSetIndicator smallint = 0
)
AS

BEGIN

    SET NOCOUNT ON



    /* ResultSet #1 */

    if (@ResultSetIndicator = 0 OR @ResultSetIndicator = 1)
    BEGIN 
        SELECT 
            c.CustomerID, c.CompanyName /*,c.ContactName,c.ContactTitle,c.[Address],c.City,c.Region,c.PostalCode,c.Country ,c.Phone,c.Fax */
        FROM 
            Customers c 
            JOIN Orders o ON c.CustomerID = o.CustomerID 
        WHERE 
            c.CustomerID = @CustomerID
    END


    /* */
    /* ResultSet #2 */ 

    if (@ResultSetIndicator = 0 OR @ResultSetIndicator = 2)
    BEGIN 

        SELECT o.OrderID,o.CustomerID /* ,o.EmployeeID,o.OrderDate,o.RequiredDate,o.ShippedDate,o.ShipVia ,o.Freight,o.ShipName,o.ShipAddress,o.OrderID,o.CustomerID,o.EmployeeID,o.OrderDate  */
        FROM 
            Orders o 
         WHERE 
            o.CustomerID = @CustomerID
        ORDER BY 
            o.CustomerID , o.OrderID 

    END


    /* */
    /* ResultSet #3 */

    if (@ResultSetIndicator = 0 OR @ResultSetIndicator = 3)
    BEGIN 
         SELECT od.OrderID,od.ProductID /* ,od.UnitPrice,od.Quantity,od.Discount  */
         FROM 
            [Order Details] od 
         WHERE 
            exists (select null from dbo.Orders  innerOrds where innerOrds.OrderID = od.OrderID and innerOrds.CustomerID = @CustomerID )
         ORDER BY 
            od.OrderID 

    END

    SET NOCOUNT OFF


END

GO 
/* Get everything */


exec dbo.uspOrderDetailsByCustomerId 'ALFKI'




    IF OBJECT_ID('tempdb..#TempCustomer') IS NOT NULL
    begin
            drop table #TempCustomer
    end


    CREATE TABLE #TempCustomer
    ( 
      [CustomerID] nchar(5)
    , [CompanyName] nvarchar(40)
    )

INSERT INTO #TempCustomer ( [CustomerID] , [CompanyName])
exec dbo.uspOrderDetailsByCustomerId 'ALFKI' , 1

Select * from #TempCustomer



    IF OBJECT_ID('tempdb..#TempOrders') IS NOT NULL
    begin
            drop table #TempOrders
    end


    CREATE TABLE #TempOrders
    ( 
        OrderID int
      , [CustomerID] nchar(5)

    )

INSERT INTO #TempOrders ( OrderID , [CustomerID] )
exec dbo.uspOrderDetailsByCustomerId 'ALFKI' , 2

Select * from #TempOrders






    IF OBJECT_ID('tempdb..#TempOrderDetails') IS NOT NULL
    begin
            drop table #TempOrderDetails
    end


    CREATE TABLE #TempOrderDetails
    ( 
        OrderID int
      , [ProductID] int

    )

INSERT INTO #TempOrderDetails ( OrderID , [ProductID] )
exec dbo.uspOrderDetailsByCustomerId 'ALFKI' , 3

Select * from #TempOrderDetails


    IF OBJECT_ID('tempdb..#TempOrderDetails') IS NOT NULL
    begin
            drop table #TempOrders
    end


    IF OBJECT_ID('tempdb..#TempOrders') IS NOT NULL
    begin
            drop table #TempOrders
    end



    IF OBJECT_ID('tempdb..#TempCustomer') IS NOT NULL
    begin
            drop table #TempCustomer
    end

It seems like there's no good simple way to do this, without a hack or a major paradigm shift. It looks like the best way is to just split out the original procs and end up with one more proc than before:

Old way:

create procedure dbo.GetSomething
as
begin
    select * from dbo.Person;
    select * from dbo.Car;
end;

New way:

create procedure dbo.GetPeople
as
begin
    select * from dbo.Person;
end;

create procedure dbo.GetCars
as
begin
    select * from dbo.Car;
end;

-- This gives the same result as before
create procedure dbo.GetSomething
as
begin
    exec dbo.GetPeople;
    exec dbo.GetCars;
end;

Then when I'm in a different proc and need both result sets, I'd just have to call them one at a time.