MVC File Upload: Object Must Implement iConvertible

Question

I'm allowing users to upload a file and give it a name. Right now, I'm just adding a row to a database with the following: Username, DataSetID (GUID), DataSetName, TimeStamp.

I'm getting the error

"Object must implement IConvertible."

Guid unique = Guid.NewGuid();
var current = DateTime.Now;
string sql = "INSERT INTO datasets (userid, datasetid, datasetname, timestamp) VALUES (@userid, @datasetid, @datasetname, @timestamp);";

using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString))
{
    using (SqlCommand command = new SqlCommand(sql, con))
    {
        command.Parameters.Add("@userid", SqlDbType.Text);
        command.Parameters["@userid"].Value = System.Web.HttpContext.Current.User.Identity.GetUserId();
        command.Parameters.Add("@datasetid", SqlDbType.Text);
        command.Parameters["@datasetid"].Value = unique;
        command.Parameters.Add("@datasetname", SqlDbType.Text);
        command.Parameters["@datasetname"].Value = datasetname.ToString();
        command.Parameters.Add("@timestamp", SqlDbType.DateTime);
        command.Parameters["@timestamp"].Value = current;


        con.Open();
        command.ExecuteNonQuery();
        con.Close();
    }
}

Answer 1

You can't implicitly convert a Guid (unique in your code) to a string.

Doing so explicitly:

command.Parameters["@datasetid"].Value = unique.ToString();

should fix it.

See https://msdn.microsoft.com/en-us/library/system.guid(v=vs.110).aspx for documentation. As you can see, Guid does not implement the IConvertible interface which would allow for implicit conversion.