PHP development: How to implement article classification function

PHP development: Implementing article classification function

Introduction: Article classification is one of the most important functions on a website or blog. Through reasonable classification, it can help users quickly locate the information they need and improve user experience. This article will introduce how to use PHP to develop and implement the article classification function, and provide specific code examples.

1. Database design

Before implementing the article classification function, you first need to design a suitable database table. Suppose we have two tables: articles and categories.

The structure of the article table is as follows:

CREATE TABLE articles (
    id INT AUTO_INCREMENT PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    content TEXT NOT NULL,
    category_id INT NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

The structure of the classification table is as follows:

CREATE TABLE categories (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(255) NOT NULL
);

2. Implement the article classification function

1. Display article classification List

First, we need to display a list of article categories to facilitate user selection. You can query the category list through the following code:

<?php
// 连接数据库
$mysqli = new mysqli("localhost", "root", "password", "database");
if ($mysqli->connect_errno) {
    die("连接数据库失败: " . $mysqli->connect_error);
}

// 查询分类列表
$result = $mysqli->query("SELECT * FROM categories");
if ($result->num_rows > 0) {
    while ($row = $result->fetch_assoc()) {
        echo "<a href='category.php?id=".$row["id"]."'>".$row["name"]."</a><br>";
    }
}

// 关闭数据库连接
$mysqli->close();
?>

The above code displays the category name as a link by querying the category table in the database. Clicking the link will jump to the corresponding category page.

2. Display a list of articles under a category

Next, we need to implement the function of displaying a list of articles under a certain category. You can query the list of articles in the corresponding category through the following code:

<?php
// 连接数据库
$mysqli = new mysqli("localhost", "root", "password", "database");
if ($mysqli->connect_errno) {
    die("连接数据库失败: " . $mysqli->connect_error);
}

// 获取分类ID
$category_id = $_GET["id"];

// 查询分类信息
$category_result = $mysqli->query("SELECT * FROM categories WHERE id = ".$category_id);
if ($category_result->num_rows > 0) {
    $category = $category_result->fetch_assoc();
    echo "<h1>".$category["name"]."</h1>";
} else {
    die("分类不存在");
}

// 查询分类下的文章列表
$articles_result = $mysqli->query("SELECT * FROM articles WHERE category_id = ".$category_id);
if ($articles_result->num_rows > 0) {
    while ($row = $articles_result->fetch_assoc()) {
        echo "<h2>".$row["title"]."</h2>";
        echo "<p>".$row["content"]."</p>";
        echo "<hr>";
    }
} else {
    echo "该分类下暂无文章";
}

// 关闭数据库连接
$mysqli->close();
?>

The above code queries the corresponding category information based on the category ID passed in the URL, and then queries the list of articles under the category and displays it.

3. Create an article and select a category

Finally, we need to implement the function of creating an article and selecting a category. This can be achieved through the following code:

<?php
// 连接数据库
$mysqli = new mysqli("localhost", "root", "password", "database");
if ($mysqli->connect_errno) {
    die("连接数据库失败: " . $mysqli->connect_error);
}

// 获取表单提交的信息
$title = $_POST["title"];
$content = $_POST["content"];
$category_id = $_POST["category_id"];

// 插入文章
$insert_result = $mysqli->query("INSERT INTO articles (title, content, category_id) VALUES ('".$title."', '".$content."', ".$category_id.")");
if ($insert_result === true) {
    echo "文章创建成功";
} else {
    echo "创建文章失败: ".$mysqli->error;
}

// 关闭数据库连接
$mysqli->close();
?>

The above code obtains the article title, content and category ID submitted by the form, and then inserts it into the article table.

Conclusion

The article classification function is one of the very common functions in websites or blogs. Through reasonable classification, user experience and information retrieval efficiency can be improved. This article introduces how to use PHP to develop and implement article classification functions, and provides specific code examples. Hope it helps all developers.

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