Question

I’ve recently changed a couple of functions recently while debugging a cte query (have gotten help here). I just changed a couple of functions.. this got my query to work.. but now when my C# client code calls those functions through stored procs for my program logic, I get the error “Procedure or function ‘DateTimeOfNextAvailableDataRun’ expects parameter ‘@NextDateTime’, which was not supplied.
” Maybe multiple values are coming back?

Here’s the function in its current form:

ALTER FUNCTION dbo.NextAvailableDataDownloadDateTime()
    RETURNS date
BEGIN
    RETURN (SELECT DATEADD(hour, 18, MIN(TradingDate)) AS TrDate
    FROM tblTradingDays
    WHERE (DATEADD(hour, 18, TradingDate) > dbo.LatestDataDownloadDate()))
END

And the stored proc that invokes it:

ALTER PROC DateTimeOfNextAvailableDataRun
    @NextDateTime DateTime2 OUTPUT
AS
    SELECT @NextDateTime = dbo.NextAvailableDataDownloadDateTime()

And lastly my client code, which did run before the change:

public DateTime DateTimeOfNxtAvailableDataRun()
            {
                DateTime dateTimeOfNxtAvailableDataRun;

                using (SqlCommand cmd = new SqlCommand("DateTimeOfNextAvailableDataRun", this.sqlConnection))
                {
                    cmd.CommandType = System.Data.CommandType.StoredProcedure;
                    cmd.ExecuteNonQuery();
                    dateTimeOfNxtAvailableDataRun = (DateTime)cmd.ExecuteScalar();
                }

                return dateTimeOfNxtAvailableDataRun;
            }

Any takers? Again, the functions work within my sql server query (see recent posts by me) but now the calling code disagrees..

Answer 1

You should modify the body of the using statement and add an output parameter before executing the command.

var outputParameter = new SqlParameter { 
    ParameterName = "@NextDateTime",
    Direction = ParameterDirection.Output
};
cmd.Parameters.Add(outputParameters);
cmd.ExecuteNonQuery();
return (DateTime)outputParameter.Value;