ajax讀取資料庫資料代碼實例:
既然ajax可以向後台發送請求,也可以傳遞參數,當然就可以根據需要進行資料庫查詢功能。
以下就透過程式碼實例介紹如何實現此需求,當然程式碼比較簡單,僅作為參考之用。
程式碼實例:
<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <meta name="author" content="http://www.php.cn/" /> <title>php中文网</title> <style> body{ font-size:12px; } </style> <script> function loadXMLDoc(keywords) { var xmlhttp; if (window.XMLHttpRequest) { xmlhttp = new XMLHttpRequest(); } else { xmlhttp = new ActiveXObject("Microsoft.XMLHTTP"); } xmlhttp.onreadystatechange = function () { if (xmlhttp.readyState == 4 && xmlhttp.status == 200) { document.getElementById("show").innerHTML = xmlhttp.responseText; } } xmlhttp.open("get", "demo/ajax/net/Query.aspx?keywords=" + escape(keywords), true); xmlhttp.send(); } window.onload = function () { var otxt = document.getElementById("txt"); var obt = document.getElementById("bt"); obt.onclick = function () { loadXMLDoc(otxt.value); } } </script> </head> <body> <input type="text" id="txt"/> <input type="button" id="bt" value="查看效果"/> (例如输入:css教程或者div教程) <div>结果:<span id="show"></span></div> </body> </html>
在文字方塊中輸入要查詢的課程名稱,然後點擊按鈕即可實現查詢效果。 asp.net後台程式碼如下:
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Data.OleDb; using System.Configuration; namespace ajax { public partial class Query : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { string keywords = Server.UrlDecode(Request.QueryString["keywords"]); if (String.IsNullOrEmpty(keywords.Trim())) { Response.Write("输入查询关键词"); Response.End(); } string connString=ConfigurationManager.ConnectionStrings["access_con"].ConnectionString; string configPath=ConfigurationManager.ConnectionStrings["access_path"].ConnectionString; string conPath = HttpContext.Current.Server.MapPath(configPath); OleDbConnection conn = new OleDbConnection(connString + conPath); string sql = "select * from data where type='" + keywords + "' order by id desc"; OleDbCommand cmd = new OleDbCommand(sql,conn); try { conn.Open(); OleDbDataReader MyReader = cmd.ExecuteReader(); if (MyReader.Read()) { Response.Write("存在指定教程"); } else { Response.Write("不存在指定教程"); } } catch (Exception ex) { throw (ex); } finally { conn.Close(); } } } }