Getting Oledb exception when updating column in excel

Question

I am getting the following error "No value given for one or more required parameters." On the ExceuteNonQuery() line of the below code.

        System.Data.OleDb.OleDbConnection finalConnection;
        System.Data.OleDb.OleDbCommand myCommand = new System.Data.OleDb.OleDbCommand();
        string sql = null;
        finalConnection = new System.Data.OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0; Data Source ='c:\\temp\\test.xlsx'; Extended Properties ='Excel 12.0 Xml;HDR=NO';");
        finalConnection.Open();
        myCommand.Connection = finalConnection;
        foreach (VinObject v in VinList)
            {
            sql = "Update [Sheet1$] set O = ? where S = ?;";
            myCommand.Parameters.Add(new OleDbParameter("@amt", v.CostNewAmt));
            myCommand.Parameters.Add(new OleDbParameter("@vin", v.VIN));
            myCommand.CommandText = sql;
            myCommand.ExecuteNonQuery();
            }
        finalConnection.Close();

I have also tried using a separate command each time, same error.

    foreach (VinObject v in VinList)
            {
            using (OleDbConnection con = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0; Data Source ='c:\\temp\\test.xlsx'; Extended Properties ='Excel 12.0 Xml;HDR=No';"))
                {
                con.Open();
                string query = @"UPDATE [Sheet1$] SET O = ? WHERE S = ?";
                OleDbCommand cmd = new OleDbCommand(query, con);
                cmd.Parameters.AddWithValue("@param1", v.CostNewAmt);
                cmd.Parameters.AddWithValue("@param2", v.VIN);
                cmd.ExecuteNonQuery();
                con.Close();
                }
            }

I am able to modify that into an insert and insert into a new excel spreadsheet, but for the life of me cannot get this update to work. Any idea what I am doing wrong? Thanks for the help.

Answer 1

You're getting the error because Excel doesn't recognize the column letter aliases "O" and "S". It needs the actual column "name", which is the value of the cell in the first populated row. If there is not a valid value in that cell, or you have specified HDR=NO in your connection string, the columns will be named F1 , F2 ... Fn . If you're not sure what the inferred column names are, examine the names using OleDbConnection.GetSchema(String,String[]) or OleDbDataReader.GetName(Int32) .

Since you have specified HDR=NO in your connection string, your correct SQL will likely be

"Update [Sheet1$] set F15 = ? where F19 = ?;"

For future reference, check out:

• How to query and display excel data by using ASP.NET, ADO.NET, and Visual C# .NET
• How to transfer data to an Excel workbook by using Visual C# 2005 or Visual C# .NET
• How To Use ADO.NET to Retrieve and Modify Records in an Excel Workbook With Visual Basic .NET . (Still lots of helpful info even if you are using C#)