Table of Contents目录
This chapter discusses the rules for writing the following elements of SQL statements when using MySQL:本章讨论在使用MySQL时编写SQL语句的以下元素的规则：
Literal values such as strings and numbers字符串和数字等文字值
Identifiers such as database, table, and column names数据库、表和列名等标识符
Keywords and reserved words关键字和保留字
User-defined and system variables用户定义和系统变量
Expressions表达
Query attributes查询属性
Comments评论