PHP implements the tag management and recommendation functions in the knowledge question and answer website.

PHP implements tag management and recommendation functions in knowledge question and answer websites

In knowledge question and answer websites, tag management is a very important function, which can help users better classify and retrieve questions. At the same time, the recommendation function can recommend relevant questions based on the user's interests and historical behavior to improve the user experience. This article will introduce how to use PHP to achieve these two functions.

Implementation of tag management function:

1. Create tag table and question table

First, we need to create a tag table (tag) and a question Table (question), used to store tag and question information. The tag table includes at least two fields: id and name, and the question table includes at least three fields: id, title, and content.

CREATE TABLE `tag` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(50) NOT NULL,
  PRIMARY KEY (`id`)
);

CREATE TABLE `question` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `title` varchar(100) NOT NULL,
  `content` text NOT NULL,
  PRIMARY KEY (`id`)
);

2. Add tags and questions

Users can select the corresponding tags when asking questions. When the user clicks the submit button, we need to insert the tag and question information into in the tag table and question table.

// 获取用户输入的标签和问题信息
$tags = $_POST['tags'];
$title = $_POST['title'];
$content = $_POST['content'];

// 插入问题信息
$query = "INSERT INTO question (title, content) VALUES ('$title', '$content')";
mysql_query($query);

// 插入标签信息
$questionId = mysql_insert_id();
foreach ($tags as $tag) {
    $query = "INSERT INTO tag (name, question_id) VALUES ('$tag', '$questionId')";
    mysql_query($query);
}

3. Retrieve questions based on tags

Users can search related questions based on tags. We can use the SQL JOIN operation to associate the label table and the question table, and then filter based on the label name.

$tag = $_GET['tag'];

$query = "SELECT q.* FROM question q
            INNER JOIN tag t ON q.id = t.question_id
            WHERE t.name = '$tag'";
$result = mysql_query($query);

while ($row = mysql_fetch_assoc($result)) {
    echo $row['title'], "<br/>";
}

Implementation of recommendation function:

1. Get tags based on user history

The recommendation function needs to get tags based on the user’s historical behavior and pass Analyze tags frequently used by users to make recommendations. We can get tags by querying questions asked by users.

$userId = $_SESSION['user_id'];

$query = "SELECT t.name FROM tag t
            INNER JOIN question q ON t.question_id = q.id
            WHERE q.user_id = '$userId'";
$result = mysql_query($query);

while ($row = mysql_fetch_assoc($result)) {
    echo $row['name'], "<br/>";
}

2. Recommend related questions based on tags

We can recommend corresponding questions based on tags that appear frequently in user history. We can use SQL's IN operation to get related questions based on the tag name.

$tags = implode(",", $userTags);

$query = "SELECT * FROM question
            WHERE id NOT IN (SELECT t.question_id FROM tag t
                              WHERE t.name IN ($tags))
            LIMIT 5";
$result = mysql_query($query);

while ($row = mysql_fetch_assoc($result)) {
    echo $row['title'], "<br/>";
}

The above is how to use PHP to implement the tag management and recommendation functions in the knowledge question and answer website. Through tag management, we can better classify and retrieve questions; through the recommendation function, we can provide relevant questions based on users' interests and historical behaviors to improve user experience. Of course, in practical applications, further expansion and optimization can be carried out according to specific needs.

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