Question

I’m writing an application which first connect to the database and retrieves a dt containing a list of all the stored procedures, inputs and their associated datatypes. The user then selected a SProc from the combobox and has to enter in the necessary inputs. The app will then connect to the database and run the selected SProc with the user specified inputs and return the results in a datatable.

What I’m unsure about is if I need to write a specific method for each SProc. I’m assuming so since I don’t see how I could state what the parameters are otherwise.

Apologies for not making this clear the first time. Let me know if this still isn’t clear enough.

Example is shown below (this is someone else’s code)

public static GetDaysDTO GetDays(int offset)
    {
        GetDaysDTO ret = new GetDaysDTO { TODAY = DateTime.Now, TOMORROW = new DateTime(2012, 01, 01) };
        SqlConnection con = new System.Data.SqlClient.SqlConnection(@"Server = FrazMan-pc\Programming; Database = master; Trusted_Connection = True");
        SqlCommand cmd = new System.Data.SqlClient.SqlCommand
        {
            CommandText = "GetDays",
            CommandType = System.Data.CommandType.StoredProcedure,
            CommandTimeout = 1,
            Connection = con,
            Parameters = { new System.Data.SqlClient.SqlParameter("@offset", System.Data.SqlDbType.Int) { Value = offset } }
        };
        using (con)
        {
            con.Open();
            using (System.Data.SqlClient.SqlDataReader reader = cmd.ExecuteReader())
            {
                while (reader.Read())
                {
                    ret.TODAY = DateTime.Parse(reader[0].ToString());
                    ret.TOMORROW = DateTime.Parse(reader["TOMORROW"].ToString());
                }
            }
        }

        return ret;
    }

Answer 1

What you’re looking for is a design pattern called Factory and a way to tell which typed data table to create on each SP call

If you have the list of the parameters for each procedure, u could instantiate the Parameters object via a loop:

This class will be used to fill the params of the sp received from the db

class ParamData
{
  public object Data;
  public SqlDbType type;
  public string ParamName;
}

and then later on, when calling the sp, u should also pass thie ParamData object to the method, and used it to fill the params of ur sp dynamicly in a loop:

List<ParamData> list = new List<ParamData>();
//initialize command here as u did
SqlCommand cmd;
foreach (ParamData param in list)
{
  SqlParameter sqlParam = new SqlParameter(param.ParamName, param.type);
  sqlParam.Value = param.Data;
  cmd.Parameters.Add(sqlParam);
}
//execute the command
//fill the datatable with result
DataTable dt = GetTableBySPName("GetDays");
SqlDataReader reader = cmd.ExecuteReader();
dt.Load(reader);

The only thing you need to add is the mapping between ur typed datatables and the returned table by the procedure.

You can add a method to do this:

private DataTable GetTableBySPName(string name)
{
  DataTable dt = null;
  switch (name)
  {
   case "GetDays":
   {
    dt = new GetDatsDTO();
    break;
   }
  }
 return dt;
}