ajax简单三层实现登陆---转载

  public class DAL
    {
        private string connstr = "Data Source=localhost;Initial Catalog=code_data;UID=sa;Password=$wuhan888;Persist Security Info=true";
        public DataTable selectDB(string sql)
        {
            DataTable dt = new DataTable();
            try
            {
                SqlConnection conn = new SqlConnection(connstr);
                SqlDataAdapter sda = new SqlDataAdapter(sql, conn);
                sda.Fill(dt);
            }
            catch (Exception e)
            { }
            return dt;
        }
    }