MySQL Tutorial

This tutorial is prepared for beginners to help them understand the basic knowledge and advanced concepts related to the MySQL language.

MySQL is the most popular relational database management system, and it is one of the best RDBMS (Relational Database Management System: relational database management system) application software for WEB applications.

In this tutorial, we will help you quickly master the basic knowledge of MySQL and easily use the MySQL database.

What is a database?

A database (Database) is a repository that organizes, stores, and manages data according to data structures.

Each database has one or more different APIs for creating, accessing, managing, searching, and replicating the saved data.

We can also store data in files, but the speed of reading and writing data in files is relatively slow.

Therefore, we now use relational database management systems (RDBMS) to store and manage large amounts of data. A relational database is a database based on the relational model, which uses mathematical concepts and methods such as set algebra to process data in the database.

The characteristics of RDBMS (Relational Database Management System):

• 1.Data is presented in tabular form

• 2.Each row corresponds to various record names

• 3.Each column corresponds to the data domain of the record name

• 4. Many rows and columns make up a table

• 5. A database is composed of several tables

RDBMS terms

Before we start learning about MySQL databases, let's first understand some terms of RDBMS:

• Database: A database is a collection of related tables.

• Data table: A table is a matrix of data. In a database, a table looks like a simple electronic spreadsheet.

• Column: A column (data element) contains data of the same type, for example, postal code data.

• Row:A row (or tuple, or record) is a set of related data, for example, a user subscription data.

• Redundancy: Stores double the data, redundancy reduces performance but improves data security.

• Primary key: The primary key is unique. A data table can only contain one primary key. You can use the primary key to query data.

• Foreign key:Foreign keys are used to associate two tables.

• Composite key: A composite key (combined key) takes multiple columns as an index key and is generally used for composite indexes.

• Index:Using indexes can quickly access specific information in the database tables. An index is a structure that sorts the values of one or more columns in a database table. It is similar to the table of contents in a book.

• Referential integrity: Referential integrity requires that there be no references to non-existent entities in the relationship. Referential integrity is one of the integrity constraints that the relational model must satisfy, with the purpose of ensuring data consistency.

MySQL is a relational database management system (RDBMS), where the term 'relational' can be understood as the concept of 'table'. A relational database is composed of one or more tables, as shown in the following table:

• Header (header): The name of each column;

• Column (col): A collection of data with the same data type;

• Row (row): Each row describes the specific information of a record;

• Value (value): Specific information of the row, each value must be the same as the data type of the column;

• Key (key): The value of the key is unique in the current column.

MySQL database

MySQL is a relational database management system developed by the Swedish company MySQL AB, which currently belongs to Oracle Corporation. MySQL is a relational database management system where data is stored in different tables rather than in a single repository, which increases speed and improves flexibility.

• MySQL is open source and currently belongs to Oracle's product line.

• MySQL supports large databases. It can handle large databases with tens of millions of records.

• MySQL uses the standard SQL data language format.

• MySQL can run on multiple systems and supports various languages. These programming languages include C and C++.++and Tcl, etc.

• MySQL has good support for PHP, which is currently the most popular web development language.

• MySQL supports large databases, supporting 5A data warehouse with 000 million records,32 The maximum table file size that the bit system can support is 4GB,64 The maximum table file size supported by the bit system is8TB.

• MySQL is customizable and uses the GPL license, allowing you to modify the source code to develop your own MySQL system.

What should you understand before starting to learn this tutorial?

Before you start learning this tutorial, you should understand the basic knowledge of PHP and HTML and be able to apply them simply.

Many examples in this tutorial are related to the PHP language, and our examples are basically demonstrated using PHP.

If you are not familiar with PHP, you can learn it through the PHP TutorialLearn this language.

　 　 MySQL is the most popular open-source relational SQL database management system. MySQL is one of the best RDBMS for developing various web-based software applications. MySQL is developed, sold, and supported by the Swedish company MySQL AB. This tutorial will give you a quick start with MySQL and make you familiar with MySQL programming.