


Let's talk about how to use MySQL to quickly implement a recommendation algorithm
This article brings you relevant knowledge about MySQL. It mainly introduces what a recommendation algorithm is, what problems this algorithm can help us solve, and how to use MySQL to implement a simple recommendation algorithm. Interested Let's take a look at it together, friends. I hope it will be helpful to everyone.
Using MySQL to implement a simple recommendation algorithm
The recommendation algorithm is a technology that is often encountered. Basically the problem solved is: if you like book A, then you'll probably like book B.
In this article, we use MySQL and disassemble and implement a simple recommendation algorithm based on data statistics.
First, create a data table of books that the user likes, which represents user_id likes book_id.
CREATE TABLE user_likes ( user_id INT NOT NULL, book_id VARCHAR(10) NOT NULL, PRIMARY KEY (user_id,book_id), UNIQUE KEY book_id (book_id, user_id) ); CREATE TABLE user_likes_similar ( user_id INT NOT NULL, liked_user_id INT NOT NULL, rank INT NOT NULL, KEY book_id (user_id, liked_user_id) );
Insert 4 pieces of test data
INSERT INTO user_likes VALUES (1, 'A'), (1, 'B'), (1, 'C'); INSERT INTO user_likes VALUES (2, 'A'), (2, 'B'), (2, 'C'), (2,'D'); INSERT INTO user_likes VALUES (3, 'X'), (3, 'Y'), (3, 'C'), (3,'Z'); INSERT INTO user_likes VALUES (4, 'W'), (4, 'Q'), (4, 'C'), (4,'Z');
means: user 1 likes A, B, C, user 2 likes A, B, C, D, user 3 likes X, Y ,C,Z, user 4 likes W,Q,C,Z.
Taking user 1 as an example to calculate recommended books, we need to calculate the similarity between user 1 and other users, and then sort according to the similarity.
Clear the similarity data table
DELETE FROM user_likes_similar WHERE user_id = 1;
Calculate the user similarity data table
INSERT INTO user_likes_similar SELECT 1 AS user_id, similar.user_id AS liked_user_id, COUNT(*) AS rank FROM user_likes target JOIN user_likes similar ON target.book_id= similar.book_id AND target.user_id != similar.user_id WHERE target.user_id = 1 GROUP BY similar.user_id ;
You can see that the found similarity result is
user_id, liked_user_id, rank 1, 2, 2 1, 3, 1 1, 4, 1
and then based on Sort by similarity, and take the top 10 books, which are the recommended books.
SELECT similar.book_id, SUM(user_likes_similar.rank) AS total_rank FROM user_likes_similar JOIN user_likes similar ON user_likes_similar.liked_user_id = similar.user_id LEFT JOIN user_likes target ON target.user_id = 1 AND target.book_id = similar.book_id WHERE user_likes_similar.user_id = 1 AND target.book_id IS NULL GROUP BY similar.book_id ORDER BY total_rank desc LIMIT 10;
[Recommended learning: mysql video tutorial]
The above is the detailed content of Let's talk about how to use MySQL to quickly implement a recommendation algorithm. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



MySQL is suitable for beginners because it is simple to install, powerful and easy to manage data. 1. Simple installation and configuration, suitable for a variety of operating systems. 2. Support basic operations such as creating databases and tables, inserting, querying, updating and deleting data. 3. Provide advanced functions such as JOIN operations and subqueries. 4. Performance can be improved through indexing, query optimization and table partitioning. 5. Support backup, recovery and security measures to ensure data security and consistency.

Navicat itself does not store the database password, and can only retrieve the encrypted password. Solution: 1. Check the password manager; 2. Check Navicat's "Remember Password" function; 3. Reset the database password; 4. Contact the database administrator.

Create a database using Navicat Premium: Connect to the database server and enter the connection parameters. Right-click on the server and select Create Database. Enter the name of the new database and the specified character set and collation. Connect to the new database and create the table in the Object Browser. Right-click on the table and select Insert Data to insert the data.

MySQL is an open source relational database management system. 1) Create database and tables: Use the CREATEDATABASE and CREATETABLE commands. 2) Basic operations: INSERT, UPDATE, DELETE and SELECT. 3) Advanced operations: JOIN, subquery and transaction processing. 4) Debugging skills: Check syntax, data type and permissions. 5) Optimization suggestions: Use indexes, avoid SELECT* and use transactions.

MySQL and SQL are essential skills for developers. 1.MySQL is an open source relational database management system, and SQL is the standard language used to manage and operate databases. 2.MySQL supports multiple storage engines through efficient data storage and retrieval functions, and SQL completes complex data operations through simple statements. 3. Examples of usage include basic queries and advanced queries, such as filtering and sorting by condition. 4. Common errors include syntax errors and performance issues, which can be optimized by checking SQL statements and using EXPLAIN commands. 5. Performance optimization techniques include using indexes, avoiding full table scanning, optimizing JOIN operations and improving code readability.

You can create a new MySQL connection in Navicat by following the steps: Open the application and select New Connection (Ctrl N). Select "MySQL" as the connection type. Enter the hostname/IP address, port, username, and password. (Optional) Configure advanced options. Save the connection and enter the connection name.

You can open phpMyAdmin through the following steps: 1. Log in to the website control panel; 2. Find and click the phpMyAdmin icon; 3. Enter MySQL credentials; 4. Click "Login".

Steps to perform SQL in Navicat: Connect to the database. Create a SQL Editor window. Write SQL queries or scripts. Click the Run button to execute a query or script. View the results (if the query is executed).
