Databases are an indispensable part of the information technology field. They play an important role in our daily lives and are everywhere from mobile applications to cloud computing. In this blog, we will delve into the basic concepts of databases and the details of MySQL, a popular open source relational database. No database expertise is required, we'll start from scratch and explain these complex concepts to you.
Basic concepts of database
What is a database?
A database is a tool or system for storing, managing, and retrieving data. Think of them as electronic filing cabinets that allow you to organize and access all kinds of information. Databases can be used for a wide range of purposes, from storing your contact list to supporting operational data for large enterprises.
Database management system (DBMS)
A database management system is a software that allows us to create, access and manage databases. DBMS is the brain of the database, responsible for processing tasks such as adding, deleting, modifying, and querying data. Common DBMS include MySQL, Oracle, Microsoft SQL Server, etc.
Database type
Databases can be divided into two main types:
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Relational database : This type of database uses tables, also known as relationships, to organize data. The table consists of rows and columns, each row represents a record and each column represents an attribute. MySQL is a popular relational database.
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Non-relational databases : These databases use different data models to store information, such as documents, key-value pairs, or graphs. For example, MongoDB is a non-relational database that stores data in the form of JSON documents.
MySQL detailed introduction
What is MySQL?
MySQL is an open source relational database management system (RDBMS) and one of the most widely used databases in the world. It has the following characteristics:
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Open source : MySQL is open source software, allowing users to use, modify and distribute it for free. This makes it the preferred database choice for many developers and organizations.
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Relational database : MySQL uses tables to organize data, and relationships can be established between these tables, making it easier to associate data.
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Multi-platform support : MySQL can run on various operating systems, including Windows, Linux, macOS, etc.
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High performance : MySQL is designed as a high-performance database, capable of handling large-scale data and high concurrent access.
MySQL development history
MySQL is a popular open source relational database management system (RDBMS). It has a rich development history and has gone through multiple versions and improvements from its inception to today. Next, let us review the development history of MySQL:
1. Birth and early development
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1979 : Swedish programmer Michael Widenius creates a simple database interface called "LISPA" (Swedish for "Little Swedish Database"). This can be seen as the predecessor of MySQL.
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1982 : Michael Widenius and David Axmark jointly developed a more powerful database management system called "UNIREG". This system is used to manage data and supports SQL language.
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1994 : In order to better support Web applications, UNIREG's development team created MySQL. The name comes from Michael Widenius's daughter My and David Axmark's daughter SQL. MySQL has become a Swedish weapon in the field of web development due to its fast, stable and lightweight characteristics.
2. MySQL AB
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1995 : MySQL AB is established to become a commercial support provider for the MySQL database. This move further promoted the development of MySQL and attracted more users and developers.
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2000 : MySQL 3.23 was released. This version introduced the InnoDB storage engine, added transaction support and foreign key constraints, making MySQL more suitable for large-scale applications.
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2001 : MySQL 4.0 was released, introducing advanced features such as subqueries, views, stored procedures, and triggers, making MySQL more powerful.
3. Sun Microsystems 和 Oracle
- 2008 : Sun Microsystems acquires MySQL AB, an acquisition that raises some concerns because Sun Microsystems was later acquired by Oracle, causing some uncertainty about the future of MySQL.
4. Open source development of MySQL
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2009 : To allay concerns about MySQL's future, Oracle pledged to continue developing and supporting MySQL and keeping it open source. This commitment helps maintain the stability and growth of the MySQL community.
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2010 : MySQL 5.5 is released, introducing more performance optimizations and improvements.
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2013 : MySQL 5.6 is released, adding full-text search capabilities, better performance and usability.
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2015 : MySQL 5.7 is released, introducing the JSON data type, better performance optimizations, and various new features.
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2016 : MySQL 8.0 is released, bringing more JSON support, window functions, universal expressions and other advanced features.
5. The present and future of MySQL
MySQL continues to be one of the most popular relational databases, widely used in web applications, enterprise solutions, and cloud computing platforms. The MySQL community continues to be active and new versions are constantly being released to adapt to evolving needs.
In the future, MySQL's development direction includes better performance, more cloud integration and stronger security. At the same time, MySQL will continue to remain active in the open source community, ensuring that it continues to be a powerful, stable and free database management system.
In short, the development history of MySQL is a classic open source success story. It has grown from a small Swedish database to a database system widely used around the world, providing reliable data management solutions for countless applications and enterprises.
Basic concepts of MySQL
database
In MySQL, a database is a container for data. You can think of a database as a folder that contains multiple tables and data related to those tables.
sheet
Tables are the main way to store data in MySQL. Each table consists of columns (fields) and rows. Columns define the type of data that can be stored in a table, while rows are the records of the actual data.
SQL
SQL (Structured Query Language) is the main way to interact with MySQL. Using SQL, you can perform a variety of operations, including querying data, inserting new data, updating existing data, and deleting data.
MySQL installation and configuration
InstallMySQL
To use MySQL on your computer, you first need to install MySQL server. You can download the installer for your operating system from the official MySQL website and follow the installation guide.
Connect to MySQL
Once MySQL is installed, you can use the MySQL client tools to connect to the database. Typically, you provide a hostname, username, and password to establish a connection.
Database operations
Create database
To create a new database you can use the following SQL command:
CREATE DATABASE mydatabase;
Create table
To create a new table in the database, you can use the following SQL command:
CREATE TABLE employees (
id INT AUTO_INCREMENT PRIMARY KEY,
first_name VARCHAR(50),
last_name VARCHAR(50),
email VARCHAR(100)
);
Insert data
To insert new data into the table, you can use the following SQL command:
INSERT INTO employees (first_name, last_name, email)
VALUES ('John', 'Doe', '[email protected]');
Query data
To retrieve data from a table, you can use the following SQL command:
SELECT * FROM employees;
update data
To update the data in the table, you can use the following SQL command:
UPDATE employees
SET email = '[email protected]'
WHERE id = 1;
delete data
To delete data from a table, you can use the following SQL command:
DELETE FROM employees
WHERE id = 1;
Database security
Database security is an important issue. It is critical to ensure that only authorized users can access and modify data. MySQL provides various security features, including user and permission management, data encryption, and firewall settings.
Performance optimization
Optimizing MySQL performance is a key aspect of database management. By using indexes, designing tables properly, optimizing queries, and configuring the database server, you can significantly improve MySQL performance.
Conclusion
In this article, we introduced the basic concepts of databases and the details of MySQL, a popular relational database. As an open source, high-performance database management system, MySQL is widely used in various applications and projects. Whether you are a newbie or an experienced developer, understanding databases and MySQL is a very important skill that can help you better manage and process data. I hope this blog will be helpful to you and give you a better understanding of the basic concepts of databases and MySQL.
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