Getting a "System.FormatException: Input string was not in a correct format." on a DateTime Object insert into MySql Database

Question

I'm working on a App using C# with Mvvm Light and a Mysql Database. When I do an insert into the Database with a parameter of an object being a DateTime object I am getting the following error:

System.FormatException: Input string was not in a correct format.
   at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
   at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
   at System.String.System.IConvertible.ToInt32(IFormatProvider provider)
   at System.Convert.ToInt32(Object value)
   at MySql.Data.Types.MySqlInt32.MySql.Data.Types.IMySqlValue.WriteValue(MySqlPacket packet, Boolean binary, Object val, Int32 length)
   at MySql.Data.MySqlClient.MySqlParameter.Serialize(MySqlPacket packet, Boolean binary, MySqlConnectionStringBuilder settings)
   at MySql.Data.MySqlClient.Statement.SerializeParameter(MySqlParameterCollection parameters, MySqlPacket packet, String parmName, Int32 parameterIndex)
   at MySql.Data.MySqlClient.Statement.InternalBindParameters(String sql, MySqlParameterCollection parameters, MySqlPacket packet)
   at MySql.Data.MySqlClient.Statement.BindParameters()
   at MySql.Data.MySqlClient.PreparableStatement.Execute()
   at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader(CommandBehavior behavior)
   at MySql.Data.MySqlClient.MySqlCommand.ExecuteNonQuery()

The Following is my view model code (proj.ProjectStartDate is a datetime object):

        DateTime startDate = projectStartDateProperty?? DateTime.Now;
        string startStr = startDate.ToString("d");
        DateTime projStart = Convert.ToDateTime(startStr);

        DateTime endDate = projectEndDateProperty ?? DateTime.Now;
        string endStr = endDate.ToString("d");
        DateTime projEnd = Convert.ToDateTime(endStr);
        proj.ProjectName = _projName;
        proj.ProjectStartDate = projStart;
        proj.ProjectEndDate = projEnd;
        proj.ProjectNotes = _projNotes;
        ProjectDbInteraction.InsertProject(_projName, proj);

With a break point set at the proj.ProjectEndDate the outcome is

And below is my Model code for the insert into the MySql Database:

    string connStr = "server=*****;database=" + projName + ";user=*****;port=*****;password=*****;";
    MySqlConnection conn = new MySqlConnection(connStr);
    MySqlCommand cmd;
    string queryInsertintoProjTable;

    try
    {
        conn.Open();
        cmd = new MySqlCommand("INSERT INTO " + projName +
        ".project(ProjectID,ProjectName,ProjectStartDate,ProjectEndDate,ProjectNotes) VALUES("
        + "(?projectid, ?projectnamecolumn,?projectstartdatecolumn,?projectenddatecolumn,?projectnotescolumn);", conn);
        cmd.Parameters.AddWithValue("?projectid", MySqlDbType.Int32).Value = proj.ProjectID;
        cmd.Parameters.AddWithValue("?projectnamecolumn", MySqlDbType.VarChar ).Value = proj.ProjectName;
        cmd.Parameters.AddWithValue("?projectstartdatecolumn", proj.ProjectStartDate.ToString("yyyy-MM-dd HH:mm:ss"));
        cmd.Parameters.AddWithValue("?projectenddatecolumn", proj.ProjectEndDate.ToString("yyyy-MM-dd HH:mm:ss"));
        cmd.Parameters.AddWithValue("?projectnotescolumn", MySqlDbType.VarChar).Value = proj.ProjectNotes;
        cmd.ExecuteNonQuery();
        conn.Close();
    }
    catch (Exception e)
    {
        Console.WriteLine(e.ToString());
    }

So what is it I need to do to fix this? This is my first time working with MySql.

Answer 1

So I found out the issue. My datetime was in fact already in the correct format. Unfortunately when parameterizing my query the Enum MySqlDbType.DateTime was throwing a false error so I just passed in the date in the AddValue.

        string connStr = "server=****;database=" + projName + ";user=***;port=****;password=****;";
        MySqlConnection conn = new MySqlConnection(connStr);
        MySqlCommand cmd;

        try
        {
            conn.Open();
            cmd = new MySqlCommand("INSERT INTO " + projName +
                ".project(ProjectID,ProjectName,ProjectStartDate,ProjectEndDate,ProjectNotes) VALUES"
                + "(?projectid, ?projectnamecolumn,?projectstartdatecolumn,?projectenddatecolumn,?projectnotescolumn);", conn);
            cmd.Parameters.AddWithValue("?projectid", proj.ProjectID);
            cmd.Parameters.AddWithValue("?projectnamecolumn", proj.ProjectName);
            cmd.Parameters.AddWithValue("?projectstartdatecolumn", proj.ProjectStartDate.ToString("yyyy-MM-dd HH:mm:ss"));
            cmd.Parameters.AddWithValue("?projectenddatecolumn", proj.ProjectEndDate.ToString("yyyy-MM-dd HH:mm:ss"));
            cmd.Parameters.AddWithValue("?projectnotescolumn", proj.ProjectNotes);
            cmd.ExecuteNonQuery();
            conn.Close();
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }

Once I removed the Enum's from the AddWithValue it worked just fine.