PHP If语句,合适吗？

Question

我正在开展一项小型大学任务,使用PHP为网站构建一个简单的电子商务引擎.

我目前有以下脚本设置来显示一个类别中的产品,所有这些都是从MySQL数据库中检索的.

http://example.com/category.php?id=2

我目前遇到的问题是,对于显示的每个产品,脚本只是简单地将每个产品并排回到新的表条目中.这导致它们跨越页面而不是垂直.

改变此代码的最佳方法是,每行最多包含三个产品？If循环或沿着这些线的东西？非常感谢支持!

<?php

//Create Session
   session_start();

//Connect to database
   include "conn.php";

//Retrieve Header
   include "header.php";

//Get Category ID 
if (isset($_GET['id'])){
    $CategoryID = $_GET['id'];

//QUERY collects product name, and product ID.
    $q="SELECT ProductID, ProductName, Price,img FROM Products WHERE CategoryID=$CategoryID";

//QUERY collects Product Category descriptions
    $d="SELECT `Desc` FROM ProductCategories WHERE CategoryID=$CategoryID";

//retrive and execute SQL query results and save into a variable
    $result = mysqli_query($_SESSION['conn'],$q);
    $result2 = mysqli_query($_SESSION['conn'],$d) or die(mysql_error());

//Retrieve Product Category Description
    echo "<div>";
    while ($myResult = mysqli_fetch_row($result2)){ //Create an array
        echo "<p>".$myResult[0]."</p>";
    }
    echo "</div>";

//Retrieve Products in category
    echo "<div align='center'><table border='1px' bordercolor='#000000' width='200px'><tr>"; //Define table, row and div containing each product

    while ($row = mysqli_fetch_row($result)){ //Create an array

        echo "<td>"; //Create table cell
        echo "<p><img src=".$row[3]."></p>"; //product image small (250x250 Pixels)
        echo "<p  align='center'><a href='product.php?id=".$row[0]."'>".$row[1]." </a></p>"; //Product ID Link and Name
        echo "<p align='center'>&#163; ".$row[2]."</p>";
        echo "</td>"; //Close table cell
    }
    echo "</tr></table></div>";//Close table, div and row
    mysqli_free_result($result);
}

// Retireve Footer
include "footer.php";
?>

在涉及任何类型的编程时,我是新手,所以我将感谢您的耐心/任何支持.此外,我知道SQL注入问题,并将在以后修复此问题.

Answer 1

那么你会用计数器跟踪你的迭代次数,然后每次你点击$counter%3 === 0(用你想要的每行替换3)你将关闭tr并开始一个新的:

$counter = 0;
$perRow = 3;
while ($row = mysqli_fetch_row($result)){ //Create an array
    if($counter === 0) {
        echo '<tr>';
    } else if ($counter%$perRow === 0 ) {
        echo '</tr><tr>';
    }
    echo "<td>"; //Create table cell
    echo "<p><img src=".$row[3]."></p>"; //product image small (250x250 Pixels)
    echo "<p  align='center'><a href='product.php?id=".$row[0]."'>".$row[1]." </a></p>"; //Product ID Link and Name
    echo "<p align='center'>&#163; ".$row[2]."</p>";
    echo "</td>";
    $counter++;
}