MySQL Pocket Reference, 2nd Edition

SQL

MySQL fully supports ANSI SQL 92, entry level. A SQL reference for MySQL is thus largely a general SQL reference. Nevertheless, MySQL contains some proprietary enhancements that can help you at the mysql command line. This section thus provides a reference for the SQL query language as it is supported in MySQL.

SQL is a kind of controlled English language consisting of verb phrases. Each of these verb phrases begins with an SQL command followed by other SQL keywords, literals, identifiers, or punctuation.

Case Sensitivity

Case-sensitivity in MySQL depends on a variety of factors, including the token in question and the underlying operating system. Table 1-3 shows the case-sensitivity of different SQL tokens in MySQL.

Table 1-3. The case-sensitivity of MySQL

Token type	Case-sensitivity
Keywords	Case-insensitive.
Identifiers (databases and tables)	Dependent on the case-sensitivity for the underlying operating system. On all Unix systems except Mac OS X using HFS+, database and table names are case-sensitive. On Mac OS X using HFS+ and Windows, they are case-insensitive.
Table aliases	Case-sensitive.
Column aliases	Case-insensitive.

Literals

Literals come in the following varieties:

String

String literals may be enclosed either by single or double quotes. If you wish to be ANSI compatible, you should always use single quotes. Within a string literal, you may represent special characters through escape sequences. An escape sequence is a backslash followed by another character to indicate to MySQL ...