1.2. Conventions Used in This Manual

MySQL 5.0

1.2. Conventions Used in This Manual

This manual uses certain typographical conventions:

  • is used for SQL statements; database, table, and column names; program listings and source code; and environment variables. Example: “To reload the grant tables, use the statement.

  • indicates input that you type in examples.

  • Text in this style indicates the names of executable programs and scripts, examples being mysql (the MySQL command line client program) and mysqld (the MySQL server executable).

  • is used for variable input for which you should substitute a value of your own choosing.

  • Filenames and directory names are written like this: “The global file is located in the directory.

  • Character sequences are written like this: “To specify a wildcard, use the ‘’ character.

  • Text in this style is used for emphasis.

  • Text in this style is used in table headings and to convey especially strong emphasis.

When commands are shown that are meant to be executed from within a particular program, the prompt shown preceding the command indicates which command to use. For example, indicates a command that you execute from your login shell, and indicates a statement that you execute from the mysql client program:

shell> 
mysql> 

The “shell” is your command interpreter. On Unix, this is typically a program such as sh, csh, or bash. On Windows, the equivalent program is command.com or cmd.exe, typically run in a console window.

When you enter a command or statement shown in an example, do not type the prompt shown in the example.

Database, table, and column names must often be substituted into statements. To indicate that such substitution is necessary, this manual uses , , and . For example, you might see a statement like this:

mysql>  FROM .;

This means that if you were to enter a similar statement, you would supply your own database, table, and column names, perhaps like this:

mysql> 

SQL keywords are not case sensitive and may be written in any lettercase. This manual uses uppercase.

In syntax descriptions, square brackets (‘’ and ‘’) indicate optional words or clauses. For example, in the following statement, is optional:

DROP TABLE [IF EXISTS] 

When a syntax element consists of a number of alternatives, the alternatives are separated by vertical bars (‘’). When one member from a set of choices may be chosen, the alternatives are listed within square brackets (‘’ and ‘’):

TRIM([[BOTH | LEADING | TRAILING] [] FROM] )

When one member from a set of choices must be chosen, the alternatives are listed within braces (‘’ and ‘’):

{DESCRIBE | DESC}  [ | ]

An ellipsis () indicates the omission of a section of a statement, typically to provide a shorter version of more complex syntax. For example, is shorthand for the form of statement that is followed by a statement.

An ellipsis can also indicate that the preceding syntax element of a statement may be repeated. In the following example, multiple values may be given, with each of those after the first preceded by commas:

RESET  [,] ...

Commands for setting shell variables are shown using Bourne shell syntax. For example, the sequence to set the environment variable and run the configure command looks like this in Bourne shell syntax:

shell> 

If you are using csh or tcsh, you must issue commands somewhat differently:

shell> 
shell>