mysql diopdownlist连接数据库,该怎么解决

mysql diopdownlist连接数据库
#region DropDownList 绑定
  protected void DropDownListBind()
  {
  string sql = "select *from tb_application";
  Common comn = new Common();
  DataSet ds = comn.GetDataSet(sql);

  ddlChapChoice.DataSource = ds.Tables[0].DefaultView;
  ddlChapChoice.DataTextField = "course";
  ddlChapChoice.DataValueField = "qid";
  ddlChapChoice.DataBound();
  }
  #endregion

表是tb_application 要的字段是course 我这样写错的 该怎么写呢？ 主键是qid

[解决办法]
protected void DropDownListBind()
{
string sql = "select *from tb_application";//空一格 select * from tb_application
Common comn = new Common();
DataSet ds = comn.GetDataSet(sql);

ddlChapChoice.DataSource = ds.Tables[0].DefaultView;
ddlChapChoice.DataTextField = "course";
ddlChapChoice.DataValueField = "qid";
ddlChapChoice.DataBound();
}