Question

Scenario

I have a stored procedure that takes a single parameter. I want to update this stored procedure to take a VARIABLE NUMBER OF PARAMETERS – a number that I will never know.
I currently use SQLConnections through a C# interface in order to pass in a single parameter to the stored procedure and return a result.

The SQL Part

Lets say that I have a stored procedure that returns a list of results based on a single input parameter “@ccy” – (Currency). Now lets say that I want to update this stored procedure to take a list of Currencies instead of a single one, but that this number will be variable depending on the situation.

The SQL Code

ALTER PROCEDURE [dbo].[SEL_BootStrapperInstRICs]
(
@ccy varchar(10)
)
AS

SELECT DISTINCT i.CCY, i.Instrument, i.Tenor, r.RIC, r.[Server], r.RIType
FROM MDR.dbo.tblBootStrapperInstruments as i, MDR.dbo.tblBootStrapperRICs as r
WHERE i.Instrument = r.MurexInstrument
AND
i.Tenor = r.Tenor
AND i.CCY = r.CCY
AND i.CCY = @ccy
AND r.RIType NOT LIKE '%forward%'

The C# Part

This particular stored procedure is called from a C# WinForms application that uses the “SqlCommand.Parameters.AddWithValue()” method. As mentioned earlier this method currently passes in a single Currency as the parameter to the stored procedure and returns the result as a DataSet.

    public DataSet GetBootStrapperInstRICsDS(List<string> ccys)
    {
        DataSet ds;
        SqlConnection dbConn = null;
        SqlCommand dbCmd = new SqlCommand();

        try
        {
            dbConn = GetSQLConnection();
            dbCmd = GetSqlCommand();
            dbCmd.CommandType = CommandType.StoredProcedure;
            dbCmd.CommandText = Utils.Instance.GetSetting     ("SELBootStrapInsRics", "default");
            foreach(string ccy in ccys)
              dbCmd.Parameters.AddWithValue("@ccy", ccy);

            dbCmd.CommandTimeout = 600;
            dbCmd.Connection = dbConn;

            SqlDataAdapter adapter = new SqlDataAdapter(dbCmd);
            ds = new DataSet();
            adapter.Fill(ds, "tblBootStrapperInstRICs");

            dbCmd.Connection.Open();

            return ds;
        }
        catch (Exception ex)
        {
            ApplicationException aex = new ApplicationException        ("GetBootStrapperInstRICsDS", ex);
            aex.Source = "Dal.GetBootStrapperInstRICsDS " + ex.Message;
            MainForm.job.Log(aex.Source, Job.MessageType.Error);
            Job.incurredErrors = true;
            throw aex;
        }
        finally
        {
            if (dbCmd != null)
                dbCmd.Dispose();
            if (dbConn != null)
            {
                dbConn.Close();
                dbConn.Dispose();
            }
        }
    }

The Question

On the C# side I think my best option is to use a “foreach/for loop” in order to iterate through a list of parameters and dynamically add a new one to the SPROC. (I have already made this update in the C# code above).

HOWEVER – Is there some way that I can do this in the SQL Stored Procedure too? My thoughts are split with two potential options – Either create 20 or more parameters in the SPROC (each with the same name but with an incrementing number at the end e.g. – @ccy1,@ccy2 etc.) and use “for(int i=0;i

    for(int i=0;i<NumberOfCurrenciesToAdd;i++)
       dbCmd.Parameters.AddWithValue("@ccy"+i, currencyArray[i]);   

Or the other option is to do something completely different and less rubbish and hack-esque. Help greatly appreciated.

EDIT – SQL Server 2005

EDIT2 – Must Use SPROCS – Company Specification Requirement.

Answer 1

You never specified SQL Server version, but for 2008 there are Table-Valued Parameters, which may help you:

Table-valued parameters are a new parameter type in SQL Server 2008. Table-valued parameters are declared by using user-defined table types. You can use table-valued parameters to send multiple rows of data to a Transact-SQL statement or a routine, such as a stored procedure or function, without creating a temporary table or many parameters.