php实现关注

PHP 实现用户关注功能

数据库设计 创建两张表：用户表（users）和关注关系表（follows）。用户表存储用户基本信息，关注关系表记录用户之间的关注关系。

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL,
    email VARCHAR(100) NOT NULL
);

CREATE TABLE follows (
    follower_id INT NOT NULL,
    following_id INT NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (follower_id, following_id),
    FOREIGN KEY (follower_id) REFERENCES users(id),
    FOREIGN KEY (following_id) REFERENCES users(id)
);

关注操作 通过INSERT语句向关注关系表中添加记录，表示一个用户关注另一个用户。

function followUser($followerId, $followingId) {
    $pdo = new PDO('mysql:host=localhost;dbname=your_database', 'username', 'password');
    $stmt = $pdo->prepare("INSERT INTO follows (follower_id, following_id) VALUES (?, ?)");
    $stmt->execute([$followerId, $followingId]);
    return $stmt->rowCount() > 0;
}

取消关注操作 使用DELETE语句从关注关系表中移除记录，表示取消关注。

function unfollowUser($followerId, $followingId) {
    $pdo = new PDO('mysql:host=localhost;dbname=your_database', 'username', 'password');
    $stmt = $pdo->prepare("DELETE FROM follows WHERE follower_id = ? AND following_id = ?");
    $stmt->execute([$followerId, $followingId]);
    return $stmt->rowCount() > 0;
}

检查关注状态 查询关注关系表，判断两个用户之间是否存在关注关系。

function isFollowing($followerId, $followingId) {
    $pdo = new PDO('mysql:host=localhost;dbname=your_database', 'username', 'password');
    $stmt = $pdo->prepare("SELECT COUNT(*) FROM follows WHERE follower_id = ? AND following_id = ?");
    $stmt->execute([$followerId, $followingId]);
    return $stmt->fetchColumn() > 0;
}

获取关注列表 查询某个用户关注的所有用户或粉丝列表。

function getFollowingList($userId) {
    $pdo = new PDO('mysql:host=localhost;dbname=your_database', 'username', 'password');
    $stmt = $pdo->prepare("SELECT u.* FROM users u JOIN follows f ON u.id = f.following_id WHERE f.follower_id = ?");
    $stmt->execute([$userId]);
    return $stmt->fetchAll(PDO::FETCH_ASSOC);
}

function getFollowerList($userId) {
    $pdo = new PDO('mysql:host=localhost;dbname=your_database', 'username', 'password');
    $stmt = $pdo->prepare("SELECT u.* FROM users u JOIN follows f ON u.id = f.follower_id WHERE f.following_id = ?");
    $stmt->execute([$userId]);
    return $stmt->fetchAll(PDO::FETCH_ASSOC);
}

注意事项 确保在操作前验证用户ID的有效性，防止无效操作。对于大规模用户系统，考虑添加索引优化查询性能。实现关注功能时，可以结合AJAX实现无刷新操作，提升用户体验。