Chapter 11 Language Structure

Table of Contents

• 11.1 Literal Values
• 11.2 Schema Object Names
• 11.3 Keywords and Reserved Words
• 11.4 User-Defined Variables
• 11.5 Expressions
• 11.6 Query Attributes
• 11.7 Comments

This chapter discusses(讨论) the rules for writing the following elements of SQL statements when using MySQL:

• Literal（字面量） values such as strings and numbers
• Identifiers such as database, table, and column names
• Keywords（关键字） and reserved words（保留字）
• User-defined and system variables（用户定义和系统变量）
• Expressions
• Query attributes
• Comments