PHP development practice: using PHP and MySQL to implement article classification function

PHP development practice: Use PHP and MySQL to implement article classification function

Introduction: In Web development, it is often necessary to implement the article classification function, which not only facilitates users to read and manage articles, but also improves the website usability and user experience. This article will introduce how to use PHP and MySQL to implement the article classification function, and come with code examples for reference.

1. Create an article classification table

We first need to create an article classification table to store the article classification information. The structure of the table is as follows:

CREATE TABLE `categories` (
 `id` INT(11) NOT NULL AUTO_INCREMENT,
 `name` VARCHAR(50) NOT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

The above statement creates a table named categories, which contains two fields: id and name. The id field is an auto-incrementing primary key, and the name field is used to store the name of the category.

2. Add article classification

Next, we need to implement the function of adding article classification. This requires adding a form to the front-end page, where the user enters the category name and submits the data to the back-end for processing. The sample code is as follows:

<form action="add_category.php" method="post">
    <label for="name">分类名称：</label>
    <input type="text" name="name" id="name">
    <input type="submit" value="添加分类">
</form>

In the back-end code add_category.php, we need to receive and process the submitted data, and then insert the category name into the database. The sample code is as follows:

<?php
// 连接数据库
$conn = mysqli_connect('localhost', 'root', 'password', 'database');

// 检查连接是否成功
if (!$conn) {
    die("连接数据库失败：" . mysqli_connect_error());
}

// 获取表单提交的分类名称
$name = $_POST['name'];

// 将分类名称插入到数据库中
$sql = "INSERT INTO categories (name) VALUES ('$name')";

if (mysqli_query($conn, $sql)) {
    echo "分类添加成功";
} else {
    echo "分类添加失败：" . mysqli_error($conn);
}

// 关闭数据库连接
mysqli_close($conn);
?>

The above code connects to the database through the mysqli_connect function, and obtains the category name submitted in the form through $_POST['name']. Then, insert the category names into the categories table.

3. Display article classification

The next step is to implement the function of displaying article classification. We can query the classified data in the database and display it on the front-end page. The sample code is as follows:

<?php
// 连接数据库
$conn = mysqli_connect('localhost', 'root', 'password', 'database');

// 检查连接是否成功
if (!$conn) {
    die("连接数据库失败：" . mysqli_connect_error());
}

// 查询数据库中的分类数据
$sql = "SELECT * FROM categories";
$result = mysqli_query($conn, $sql);

// 输出分类数据
if (mysqli_num_rows($result) > 0) {
    while ($row = mysqli_fetch_assoc($result)) {
        echo $row['name'] . "<br>";
    }
} else {
    echo "暂无分类数据";
}

// 关闭数据库连接
mysqli_close($conn);
?>

The above code queries the data in the categories table through the mysqli_query function, and uses the mysqli_fetch_assoc function to obtain each row of data in the query result. Then, display the category name on the front-end page.

4. Association between articles and categories

The last step is to realize the association between articles and categories. We can add a category_id field to the article table to store the category ID of the article. The sample code is as follows:

ALTER TABLE articles ADD category_id INT(11) AFTER content;

In the subsequent article publishing and editing process, you can select the category to which the article belongs through the drop-down menu and save the category ID in the database. According to needs, we can also implement functions such as retrieval and display of articles according to categories.

Conclusion: This article introduces how to use PHP and MySQL to implement the article classification function. By creating an article classification table, adding article categories, displaying article categories, and associating articles and categories, we can implement a complete article classification function. I hope this article can provide some help to the article classification problems encountered by PHP developers in practice.

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