MySql sub-table, how do large companies do it, how to do it efficiently, how to do joint table query between sub-tables?

MySQL and phpMyAdmin are powerful database management tools. 1) MySQL is used to create databases and tables, and to execute DML and SQL queries. 2) phpMyAdmin provides an intuitive interface for database management, table structure management, data operations and user permission management.

In MySQL, the function of foreign keys is to establish the relationship between tables and ensure the consistency and integrity of the data. Foreign keys maintain the effectiveness of data through reference integrity checks and cascading operations. Pay attention to performance optimization and avoid common errors when using them.

IIS and PHP are compatible and are implemented through FastCGI. 1.IIS forwards the .php file request to the FastCGI module through the configuration file. 2. The FastCGI module starts the PHP process to process requests to improve performance and stability. 3. In actual applications, you need to pay attention to configuration details, error debugging and performance optimization.

The main difference between MySQL and MariaDB is performance, functionality and license: 1. MySQL is developed by Oracle, and MariaDB is its fork. 2. MariaDB may perform better in high load environments. 3.MariaDB provides more storage engines and functions. 4.MySQL adopts a dual license, and MariaDB is completely open source. The existing infrastructure, performance requirements, functional requirements and license costs should be taken into account when choosing.

Multiple calls to session_start() will result in warning messages and possible data overwrites. 1) PHP will issue a warning, prompting that the session has been started. 2) It may cause unexpected overwriting of session data. 3) Use session_status() to check the session status to avoid repeated calls.

SQL is a standard language for managing relational databases, while MySQL is a database management system that uses SQL. SQL defines ways to interact with a database, including CRUD operations, while MySQL implements the SQL standard and provides additional features such as stored procedures and triggers.

AI can help optimize the use of Composer. Specific methods include: 1. Dependency management optimization: AI analyzes dependencies, recommends the best version combination, and reduces conflicts. 2. Automated code generation: AI generates composer.json files that conform to best practices. 3. Improve code quality: AI detects potential problems, provides optimization suggestions, and improves code quality. These methods are implemented through machine learning and natural language processing technologies to help developers improve efficiency and code quality.

MySQL and phpMyAdmin can be effectively managed through the following steps: 1. Create and delete database: Just click in phpMyAdmin to complete. 2. Manage tables: You can create tables, modify structures, and add indexes. 3. Data operation: Supports inserting, updating, deleting data and executing SQL queries. 4. Import and export data: Supports SQL, CSV, XML and other formats. 5. Optimization and monitoring: Use the OPTIMIZETABLE command to optimize tables and use query analyzers and monitoring tools to solve performance problems.