Question

我的数据库中有一个表。

Employee
___________________________________
| Name      |   City              |    
___________________________________
| Jack      |  UK                 |
___________________________________
| John      |  Kenya              |
___________________________________

我使用选择查询从此表中获取值这是来自Employee的选择数据的sql.php文件。

<?php
$con=mysqli_connect("localhost","root","","company");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

$result = mysqli_query($con,"SELECT * FROM employee");

while($row = mysqli_fetch_array($result))
  {
  echo $row['name'] . "&nbsp" . $row['city'];
  }

mysqli_close($con);
?>

现在我试着长时间拉这是长拉的简单代码： -

<html>
<head>
    <title>BargePoller</title>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js" type="text/javascript" charset="utf-8"></script>

    <style type="text/css" media="screen">
      body{ background:#000;color:#fff;font-size:.9em; }
      .msg{ background:#aaa;padding:.2em; border-bottom:1px #000 solid}
      .old{ background-color:#246499;}
      .new{ background-color:#3B9957;}
    .error{ background-color:#992E36;}
    </style>

    <script type="text/javascript" charset="utf-8">
    function addmsg(type, msg){
        /* Simple helper to add a div.
        type is the name of a CSS class (old/new/error).
        msg is the contents of the div */
        $("#messages").append(
            "<div class='msg "+ type +"'>"+ msg +"</div>"
        );
    }

    function waitForMsg(){
        /* This requests the url "msgsrv.php"
        When it complete (or errors)*/
        $.ajax({
            type: "GET",
            url: "sql.php",

            async: true, /* If set to non-async, browser shows page as "Loading.."*/
            cache: false,
            timeout:1000, /* Timeout in ms */

            success: function(data){ /* called when request to barge.php completes */
                addmsg("new", data); /* Add response to a .msg div (with the "new" class)*/
                setTimeout(
                    waitForMsg, /* Request next message */
                    1000 /* ..after 1 seconds */
                );
            },
            error: function(XMLHttpRequest, textStatus, errorThrown){
                addmsg("error", textStatus + " (" + errorThrown + ")");
                setTimeout(
                    waitForMsg, /* Try again after.. */
                    1000); /* milliseconds (15seconds) */
            }
        });
    };

    $(document).ready(function(){
        waitForMsg(); /* Start the inital request */
    });
    </script>
</head>
<body>
    <div id="messages">
        <div class="msg old">
            BargePoll message requester!
        </div>
    </div>
</body>
</html>

它的工作完美，ajax呼叫每一秒但我想设置如果在表中进行任何更改，那么它在我的页面上的附加div其他明智的没有。
我怎么能这样做。
感谢。

Answer 1

你应该将轮询间隔从1秒增加到15秒，你没事。

真实的通知系统 - 就像在StackExchange上一样 - 需要基于web socket的解决方案。另外，你需要在mysql中存储一些存储过程 - 注册为触发器函数 - 它们可以与Web套接字服务器通信。

如果记录是新的，长期拉动

1 个答案: