MySQL includes character set support that enables you to store data using a variety of character sets and perform comparisons according to a variety of collations. MySQL包括字符集支持，使您能够使用各种字符集存储数据，并根据各种排序规则进行比较。The default MySQL server character set and collation are utf8mb4 and utf8mb4_0900_ai_ci, but you can specify character sets at the server, database, table, column, and string literal levels.默认的MySQL服务器字符集和排序规则是utf8mb4和utf8mb4_0900_ai_ci，但您可以在服务器、数据库、表、列和字符串文字级别指定字符集。

This chapter discusses the following topics:本章讨论以下主题：

Character set issues affect not only data storage, but also communication between client programs and the MySQL server. 字符集问题不仅会影响数据存储，还会影响客户端程序和MySQL服务器之间的通信。If you want the client program to communicate with the server using a character set different from the default, you'll need to indicate which one. 如果您希望客户端程序使用不同于默认值的字符集与服务器通信，则需要指明是哪一个字符集。For example, to use the utf8 Unicode character set, issue this statement after connecting to the server:例如，要使用utf8 Unicode字符集，请在连接到服务器后发出以下语句：

SET NAMES 'utf8';

For more information about configuring character sets for application use and character set-related issues in client/server communication, see Section 10.5, “Configuring Application Character Set and Collation”, and Section 10.4, “Connection Character Sets and Collations”.有关为应用程序使用配置字符集以及客户端/服务器通信中与字符集相关的问题的更多信息，请参阅第10.5节，“配置应用程序字符集和排序规则”和第10.4节，“连接字符集和排列规则”。