購物車基本功能：商品的添加、修改、刪除、結算、和分頁查詢
文件的基本組織形式：shopcar_display.php（購物車裏面的商品展示頁面 具有分頁功能）
shopcar_ajax.js(提交當前頁數)
shopcar_session.php(生成當前頁面的購物車裏面的記錄session數據)
分頁細節展示
shopcar_display.php
<body>
<?php
include("index_top_nav.php");
?>
<div class = "wrap">
<nav class="navbar navbar-default">
<p class="navbar-text p1">商品</p>
<p class="navbar-text p2">價格</p>
<p class="navbar-text p3">數量</p>
<p class="navbar-text p4">總計</p>
</nav>
<?php
$connID = mysqli_connect("127.0.0.1","root","","shop");
mysqli_query($connID,"set names utf8");
$query = "SELECT `name`, `price`, `number`, `total` FROM `".$_SESSION['name']."_car`";
$result = mysqli_query($connID,$query);
//獲取總共有多少條數據
$count = mysqli_num_rows($result);
//先計算一共有多少頁 每頁六個數據
if($count%6 ==0){
$pageNum = $count/6;
}else{
$pageNum = intval($count/6)+1;
}
$index=0;
foreach($_SESSION['result'] as $key => $value){?>
<div class="panel panel-default">
<div class = " img"><img src="image/20191001.jpg" alt="..."/></div>
<div class = "panel-body id"><?php echo $value[0];?></div>
<div class = "panel-body id"><?php echo $value[1];?></div>
<div class = "panel-body id"><?php echo $value[2];?></div>
<div class = "panel-body id"><?php echo $value[3];?></div>
</div>
<?php
}
?>
<nav aria-label="Page navigation">
<ul class="pagination">
<li>
<a href="#" aria-label="Previous">
<span aria-hidden="true">«</span>
</a>
</li>
<?php
$index = 1;
while($pageNum > 0){?>
<li class = "Liindex"><a href="#"><?php echo $index?></a></li>
<?php
$index ++;
$pageNum --;
}
?>
<li>
<a href="#" aria-label="Next">
<span aria-hidden="true">»</span>
</a>
</li>
</ul>
</nav>
</div>
<script src = "js/shopcar_ajax.js"></script>
</body>
基本思路解析：首先訪問該用戶的購物車表文件，獲取一共有多少條數據，然後計算需要分幾頁，最後生成分頁按鈕導航,當前頁面訪問的$_SESSION['result']數據是在shopcar_session.php中生成的。
分頁具體實現（shopcar_ajax.js + shopcar_session.php）
GetCurrenIndex(1);
var allLi = document.getElementsByClassName("liindex");
for(var index = 0;index<allLi.length;index++){
allLi[index].addEventListener("click",function(){
GetCurrenIndex(this.firstElementChild.innerHTML);
location.reload();
console.log(this.firstElementChild.innerHTML);
})
}
function GetCurrenIndex(current){
var xmlHttp = new XMLHttpRequest();
url = "shopcar_session.php?current="+current;
xmlHttp.open("get",url,true);
xmlHttp.send(null);
xmlHttp.onreadystatechange = function(){
if(xmlHttp.readyState == 4 && xmlHttp.status == 200){
console.log(xmlHttp.responseURL);
}
}
}
js裏面提交用戶當前是要訪問第幾頁數據，給每一個分頁按鈕綁定單擊事件和ajax提交數據.
<?php
session_start();
$_SESSION['result'] = array();
include("conn/conn.php");
$query = "SELECT `name`, `price`, `number`, `total` FROM `".$_SESSION['name']."_car` limit ".strval((intval($_GET["current"])-1)*6).",6";
$result = mysqli_query($connID,$query);
$index = 0;
while($arr = mysqli_fetch_array($result,MYSQLI_NUM)){
$_SESSION['result'][$index] = $arr;
$index ++;
}
?>
獲取用戶提交來的ajax當前頁面，然後計算需要查詢數據限制在那幾條。其中這裏學習到的新的查詢限定關鍵字limit，然後生成session數據，最後在shopcar_display中訪問session數據.顯示分頁和展示的功能.