Wrong number of parameters (parametrized query)

Question

Q:

When i try to execute the following parametrized query:

INSERT INTO days (day,short,name,depcode,studycode,batchnum) values (?,?,?,?,?,?);SELECT SCOPE_IDENTITY();

through command.ExecuteScalar();

throws the following exception:

ERROR [07001] [Informix .NET provider]Wrong number of parameters.

Where is the problem?

EDIT:

 public static int InsertDays(List<Day> days)
        {

            int affectedRow = -1;
            Dictionary<string, string> daysParameter = new Dictionary<string, string>();
            try
            {
                foreach (Day a in days)
                {
                    daysParameter.Add("day", a.DayId.ToString());
                    daysParameter.Add("short", a.ShortName);
                    daysParameter.Add("name", a.Name);
                    daysParameter.Add("depcode", a.DepCode.ToString());
                    daysParameter.Add("studycode", a.StudyCode.ToString());
                    daysParameter.Add("batchnum", a.BatchNum.ToString());

                    affectedRow = DBUtilities.InsertEntity_Return_ID("days", daysParameter);
                    daysParameter.Clear();
                    if (affectedRow < 0)
                    {
                        break;
                    }
                }
            }
            catch (Exception ee)
            {
                string message = ee.Message;
            }

            return affectedRow;

        }

---

public static int InsertEntity_Return_ID(string tblName, Dictionary<string, string> dtParams)
        {
            int Result = -1;
            DBConnectionForInformix DAL_Helper = new DBConnectionForInformix("");
            string[] field_names = new string[dtParams.Count];
            dtParams.Keys.CopyTo(field_names, 0);
            string[] field_values = new string[dtParams.Count];
            string[] field_valuesParam = new string[dtParams.Count];
            dtParams.Values.CopyTo(field_values, 0);
            for (int i = 0; i < field_names.Length; i++)
            {
                field_valuesParam[i] = "?";
            }
            string insertCmd = @"INSERT INTO " + tblName + " (" + string.Join(",", field_names) + ") values (" + string.Join(",", field_valuesParam) + ");SELECT SCOPE_IDENTITY();";

        Result = int.Parse(DAL_Helper.Return_Scalar(insertCmd));
        return Result;
        }

---

Answer 1

You haven't shown where you're actually populating the parameter values. Given that you've got the right number of question marks, I suspect that's where the problem lies.

EDIT: Okay, now you've posted more code, it's obvious what's going wrong: your Return_Scalar method isn't accepting any actual values! You're not using field_values anywhere after populating it. You need to set the parameters in the command.

(You should also look at .NET naming conventions, by the way...)