How to Implement Data Persistence for a Mutual Follow System in PHP? A Detailed Guide on Three Approaches

How to Implement Data Persistence for a Mutual Follow System in PHP? A Detailed Guide on Three Approaches

With the rise of social platforms, the mutual follow system has become one of the key features in many social networks. From Weibo to WeChat, these platforms use the follow functionality as an important part of user interaction. For PHP developers, implementing data persistence for a mutual follow system is a critical issue to address.

1. File Storage: Simple but with Limitations

File storage is one of the most basic ways to persist data. In simple terms, follow relationships can be stored in a text file, with each line representing a follow relationship between users. For example, the text format might be “User A follows User B,” and when User A unfollows User B, the corresponding line can be deleted.

However, file storage is only suitable for small-scale data. For large-scale user data, the performance becomes poor, and it does not support high concurrent operations. Concurrent reads and writes could result in file corruption or data inconsistency. Therefore, for systems that require frequent read and write operations, such as a mutual follow system, file storage is not recommended.

2. Database Storage: An Ideal Choice for Structured Data

Database storage is the most common and efficient method of data persistence, especially for applications that need to handle large amounts of data. In PHP development, relational databases like MySQL or PostgreSQL, and non-relational databases like MongoDB, are often used.

For example, using MySQL, two tables can be created: one to store user information and another to store the follow relationships. This ensures data integrity through foreign key constraints. Below is an example of the database table structure in MySQL:

User Table Structure

CREATE TABLE users (
    id INT(11) PRIMARY KEY AUTO_INCREMENT,
    username VARCHAR(50) NOT NULL,
    password VARCHAR(255) NOT NULL
);

Follow Relationship Table Structure

CREATE TABLE followings (
    id INT(11) PRIMARY KEY AUTO_INCREMENT,
    user_id INT(11) NOT NULL,
    target_user_id INT(11) NOT NULL,
    FOREIGN KEY (user_id) REFERENCES users(id),
    FOREIGN KEY (target_user_id) REFERENCES users(id)
);

In PHP code, you can use PDO or mysqli to connect to the database and execute corresponding SQL statements for inserting, deleting, and querying data. This method is highly suitable for scenarios requiring the processing of large-scale data and high concurrent operations.

3. Cache Storage: Efficient Temporary Data Storage

Cache technologies like Redis and Memcached can significantly speed up data retrieval. Storing follow relationships in memory allows for very fast read and write operations.

For example, with Redis, PHP code can use the Redis extension to connect, and then use Redis commands (such as set and get) to store and retrieve follow relationships.

However, it’s important to note that cache storage is temporary, and data may be lost due to cache expiration or service restarts. Therefore, when using cache storage, a data persistence strategy should be considered, such as backing up data to a database to prevent loss.

Conclusion

In summary, there are several ways to implement data persistence for a mutual follow system in PHP. File storage is simple but not suitable for large-scale data. Database storage is ideal for handling large amounts of data, offering transaction support and data consistency. Cache storage provides fast read and write operations but comes with the risk of data loss, requiring a persistence strategy.

Depending on the project requirements, system scale, and performance needs, developers can choose the most suitable storage method to implement an efficient and stable mutual follow system.