Dropdownlist与数据库绑定

1、Dropdownlist与数据库绑定。

string sql_subject="select subject from
tt_subject";

            OleDbConnection Conn=db.okConn();

           
Conn.Open();

            OleDbCommand cmd = new OleDbCommand(sql_subject,
Conn); //这里从数据库中读入到Dropdownlist

            OleDbDataReader reader =
cmd.ExecuteReader();

            Dropdownlist9.DataSource =
reader;

            Dropdownlist9 .DataTextField
="subject";//字段

            Dropdownlist9.DataValueField =
"subject";

            Dropdownlist9 .DataBind ();