Mysql语法错误

我收到以下错误，找不到问题:

你的SQL语法有错误;检查与你的MySQL服务器版本对应的手册，以便在第1行"字符串"，"字符串"，"6"，"字符串"，"字符串"，"字符串"，"the"附近使用正确的语法

c#代码:

    protected void updateDB(byte[] content, int size, string mime)
{
    string school = DropDownList_School.Text;
    string subject = DropDownList_Subject.Text;
    string teacher = DropDownList_Teacher.Text;
    string course = DropDownList_Class.Text;
    string unit = TextBox_Unit.Text;
    string name = TextBox_Name.Text;
    string date = DateTime.Today.ToString();
    string username = System.Web.Security.Membership.GetUser().UserName;
    MySqlConnection connection = new MySqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["MySqlConnection"].ConnectionString);
    connection.Open();
    MySqlCommand cmd = new MySqlCommand();//(query, connection);
    cmd.Connection = connection;
    cmd.CommandText = "INSERT INTO uploads 
                       (@School, @Subject, @Teacher, @Course, @Unit, @Name, @Username, @Size, @MIME, @content) ";
    cmd.Prepare();
    cmd.Parameters.AddWithValue("@School", school);
    cmd.Parameters.AddWithValue("@Subject", subject);
    cmd.Parameters.AddWithValue("@Teacher", teacher);
    cmd.Parameters.AddWithValue("@Course", course);
    cmd.Parameters.AddWithValue("@Unit", unit);
    cmd.Parameters.AddWithValue("@Name", name);
    cmd.Parameters.AddWithValue("@Username", username);
    cmd.Parameters.AddWithValue("@Size", size);
    cmd.Parameters.AddWithValue("@MIME", mime);
    cmd.Parameters.AddWithValue("@content", content);
    cmd.ExecuteNonQuery();
    connection.Close();
}

ConnectionString正确