mysql-front简介

MySQL-简介 (MySQL - Introduction)

什么是数据库？ (What is a Database?)

A database is a separate application that stores a collection of data. Each database has one or more distinct APIs for creating, accessing, managing, searching and replicating the data it holds.

数据库是存储数据集合的独立应用程序。 每个数据库都有一个或多个不同的API，用于创建，访问，管理，搜索和复制其拥有的数据。

Other kinds of data stores can also be used, such as files on the file system or large hash tables in memory but data fetching and writing would not be so fast and easy with those type of systems.

也可以使用其他类型的数据存储，例如文件系统上的文件或内存中的大型哈希表，但是使用这些类型的系统，数据的获取和写入将不那么快捷，容易。

Nowadays, we use relational database management systems (RDBMS) to store and manage huge volume of data. This is called relational database because all the data is stored into different tables and relations are established using primary keys or other keys known as Foreign Keys.

如今，我们使用关系数据库管理系统(RDBMS)来存储和管理大量数据。 之所以称为关系数据库，是因为所有数据都存储在不同的表中，并且使用主键或称为外键的其他键来建立关系。

A Relational DataBase Management System (RDBMS) is a software that −

关系数据库管理系统(RDBMS)是一种软件，该软件-

• Enables you to implement a database with tables, columns and indexes.

  使您能够使用表，列和索引来实现数据库。

• Guarantees the Referential Integrity between rows of various tables.

  确保各种表的行之间的引用完整性。

• Updates the indexes automatically.

  自动更新索引。

• Interprets an SQL query and combines information from various tables.

  解释SQL查询并合并来自各个表的信息。

RDBMS术语 (RDBMS Terminology)

Before we proceed to explain the MySQL database system, let us revise a few definitions related to the database.

在继续解释MySQL数据库系统之前，让我们修改一些与数据库有关的定义。

• Database − A database is a collection of tables, with related data.

  数据库 -数据库是具有相关数据的表的集合。

• Table − A table is a matrix with data. A table in a database looks like a simple spreadsheet.

  表格 -表格是包含数据的矩阵。 数据库中的表看起来像一个简单的电子表格。

• Column − One column (data element) contains data of one and the same kind, for example the column postcode.

  列 -一列(数据元素)包含一种相同类型的数据，例如列邮政编码。

• Row − A row (= tuple, entry or record) is a group of related data, for example the data of one subscription.

  行 -行(=元组，条目或记录)是一组相关数据，例如一个订阅的数据。

• Redundancy − Storing data twice, redundantly to make the system faster.

  冗余 -两次存储数据，以提高系统速度。

• Primary Key − A primary key is unique. A key value can not occur twice in one table. With a key, you can only find one row.

  主键 -主键是唯一的。 一个表中的键值不能出现两次。 使用密钥，您只能找到一行。

• Foreign Key − A foreign key is the linking pin between two tables.

  外键 -外键是两个表之间的链接销。

• Compound Key − A compound key (composite key) is a key that consists of multiple columns, because one column is not sufficiently unique.

  复合键 -复合键(复合键)是由多列组成的键，因为一列不够唯一。

• Index − An index in a database resembles an index at the back of a book.

  索引 -数据库中的索引类似于书后部的索引。

• Referential Integrity − Referential Integrity makes sure that a foreign key value always points to an existing row.

  引用完整性 -引用完整性可确保外键值始终指向现有行。

MySQL数据库 (MySQL Database)

MySQL is a fast, easy-to-use RDBMS being used for many small and big businesses. MySQL is developed, marketed and supported by MySQL AB, which is a Swedish company. MySQL is becoming so popular because of many good reasons −

MySQL是一种快速，易于使用的RDBMS，可用于许多大小企业。 MySQL由瑞典公司MySQL AB开发，销售和支持。 由于许多原因，MySQL变得如此流行-

• MySQL is released under an open-source license. So you have nothing to pay to use it.

  MySQL是在开源许可证下发布的。 因此，您无需付费即可使用它。

• MySQL is a very powerful program in its own right. It handles a large subset of the functionality of the most expensive and powerful database packages.

  MySQL本身就是一个非常强大的程序。 它处理最昂贵和功能最强大的数据库程序包的大部分功能。

• MySQL uses a standard form of the well-known SQL data language.

  MySQL使用众所周知SQL数据语言的标准形式。

• MySQL works on many operating systems and with many languages including PHP, PERL, C, C++, JAVA, etc.

  MySQL可在许多操作系统上运行，并支持多种语言，包括PHP，PERL，C，C ++，JAVA等。

• MySQL works very quickly and works well even with large data sets.

  MySQL可以非常快速地运行，并且即使对于大型数据集也可以很好地运行。

• MySQL is very friendly to PHP, the most appreciated language for web development.

  MySQL对PHP非常友好，PHP是Web开发中最受欢迎的语言。

• MySQL supports large databases, up to 50 million rows or more in a table. The default file size limit for a table is 4GB, but you can increase this (if your operating system can handle it) to a theoretical limit of 8 million terabytes (TB).

  MySQL支持大型数据库，一个表中最多有5000万行或更多行。 表的默认文件大小限制为4GB，但您可以将其增加(如果操作系统可以处理)，理论上可以达到800万兆字节(TB)。

• MySQL is customizable. The open-source GPL license allows programmers to modify the MySQL software to fit their own specific environments.

  MySQL是可定制的。 开源GPL许可证允许程序员修改MySQL软件以适合他们自己的特定环境。

在你开始之前 (Before You Begin)

Before you begin this tutorial, you should have a basic knowledge of the information covered in our PHP and HTML tutorials.

在开始本教程之前，您应该对我们PHP和HTML教程中所包含的信息有基本的了解。

This tutorial focuses heavily on using MySQL in a PHP environment. Many examples given in this tutorial will be useful for PHP Programmers.

本教程着重于在PHP环境中使用MySQL。 本教程中给出的许多示例对于PHP程序员都是有用的。

We recommend you check our PHP Tutorial for your reference.

我们建议您检查我们的PHP教程以供参考。

翻译自: https://www.tutorialspoint.com/mysql/mysql-introduction.htm

mysql-front简介