Question

I have a stored procedure that returns a list. Now I’m trying to write a function that will pass the stored procedure that correct parameter and then return the list so that it can be used on asp web page. I’m completely lost.

I’ve tried this so far to no avail

public static List<RetrieveActiveMuseumByMuseumID_Result> GetActiveMuseum()
{
     using (MuseumDB db = new MuseumDB(ConfigurationManager.ConnectionStrings["MuseumDB"].ConnectionString))
     {
          List<RetrieveActiveMuseumByMuseumID_Result> listOrdered = new List<RetrieveActiveRigsWithEquipmentByOffice_Result>();
     }
  return listOrdered;
 }

But that doesn’t do anything and it doesn’t pass the parameter of the SP which is @MuseumID

Help please I don’t know where to go from here.

Answer 1

For Asp.net data sources: List == bad, Enumerable == good. Both can be used as a data source, but enumerables tend to perform better, especially for asp.net where memory use is so important. Lists force you to have the entire result set in memory. Play your cards right with an enumerable, and you may only need one record in memory at a time.

public static IEnumerable<RetrieveActiveMuseumByMuseumID_Result> GetActiveMuseum()
{
     using (var cn = new SqlConnection(ConfigurationManager.ConnectionStrings["MuseumDB"].ConnectionString))
     using (var cmd = new SqlCommand("StoredProcedureName", cn)
     {
          cmd.CommandType = CommandTypes.StoredProcedure;
          //you need to supply some of the information for this line: you didn't include it in your question
          cmd.Parameters.Add("@ParameterName", SqlDbTypes.???).Value = ParameterValue;

          cn.Open();
          using (var rdr = cmd.ExecuteReader())
          {
               while (rdr.Read())
               {  //you'll need to implement the static create method I used here
                   yield return new RetrieveActiveMuseumByMuseumID_Result.Create(rdr);
               }
          }
     }
 }

To make this work, your RetrieveActiveMuseumByMuseumID_Result type needs a static Create() method that accepts an IDataRecord and return a new RetrieveActiveMuseumByMuseumID_Result object (this follows the Factory pattern).

I tend to abstract this pattern away to a “mini-ORM”, using a generic method that looks like this:

public static IEnumerable<IDataRecord> GetData(string command, Action<SqlParameterCollection> addParameters)
{
    using (var cn = new SqlConnection( /* generic code for connection string here */ ));
    using (var cmd = new SqlCommand(command, cn))
    {
        addParameters(cmd.Parameters);

        cn.Open();
        using (var rdr = cmd.ExecuteReader())
        {
            while (rdr.Read())
            {
                yield return rdr;
            }
        }
    }
}

And then I would call that for your query like this:

public static IEnumerable<RetrieveActiveMuseumByMuseumID_Result> GetActiveMuseum()
{ 
     return GetData("exec StoredProcedureName @ParameterName", p => 
          {
             p.Add("@ParameterName", SqlDbTypes.???).Value = ParameterValue;
          }).Select(r => RetrieveActiveMuseumByMuseumID_Result.Create(r));
}