1.1 About This Guide

This guide is made up of those chapters from the MySQL Reference Manual that focus on database administration topics. It covers software installation, server configuration and day-to-day operation, table maintenance, and replication. A companion guide, the MySQL Language Reference , serves as a reference to the SQL language used to perform database queries in MySQL. It covers language structure, functions and operators, column types, and SQL statement syntax.

This guide is current up to MySQL 5.0.1, but is also applicable for older versions of the MySQL software (such as 3.23 or 4.0-production) because functional changes are indicated with reference to a version number.

Because this guide serves as a reference, it does not provide general instruction on SQL or relational database concepts. It also will not teach you how to use your operating system or command line interpreter.

The MySQL Database Software is under constant development, and the Reference Manual is updated frequently as well. The most recent version of the manual is available online in searchable form at http://dev.mysql.com/doc/. Other formats also are available, including HTML, PDF, and Windows CHM versions.

If you have any suggestions concerning additions or corrections to this manual, please send them to the documentation team at [e-mail].

This manual was initially written by David Axmark and Michael "Monty" Widenius. It is now maintained by the MySQL Documentation Team, consisting of Arjen Lentz, Paul DuBois, and Stefan Hinz.

The copyright (2004) to this manual is owned by the Swedish company MySQL AB. See Section 1.4.2, "Copyrights and Licenses Used by MySQL."

1.1.1 Conventions Used in This Manual

This manual uses certain typographical conventions:

• constant

  Constant-width font is used for command names and options; SQL statements; database, table, and column names ; C and Perl code; filenames; URLs; and environment variables . Example: "To see how mysqladmin works, invoke it with the --help option."

• constant bold

  Bold constant-width font is used to indicate input that you type in examples.

• constant italic

  Italic constant-width font is used to indicate variable input for which you should substitute a value of your own choosing.

• ' c '

  Constant-width font with surrounding quotes is used to indicate character sequences. Example: "To specify a wildcard, use the ' % ' character."

• italic

  Italic font is used for emphasis, like this .

• boldface

  Boldface font 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 program is indicated by a prompt shown before the command. For example, shell> indicates a command that you execute from your login shell, and mysql> indicates a statement that you execute from the mysql client program.

 shell>  type a shell command here  mysql>  type a mysql statement here  

The "shell" is your command interpreter. On Unix, this is typically a program such as sh or csh . 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.

In example commands, input that you type is indicated in bold type. Variable input for which you should substitute a value that you choose is indicated in italic type. Database, table, and column names must often be substituted into statements. To indicate that such substitution is necessary, this manual uses db_name , tbl_name , and col_name . For example, you might see a statement like this:

 mysql>  SELECT   col_name   FROM   db_name   .   tbl_name   ;  

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>  SELECT author_name FROM biblio_db.author_list;  

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

In syntax descriptions, square brackets (' [ ' and ' ] ') are used to indicate optional words or clauses. For example, in the following statement, IF EXISTS is optional:

 DROP TABLE [IF EXISTS]  tbl_name  

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] [  remstr  ] FROM]  str  ) 

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

 {DESCRIBE  DESC}  tbl_name  [  col_name   wild  ] 

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

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

 RESET  reset_option  [,  reset_option  ] ... 

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

 shell>  VARNAME   =   value some_command  

If you are using csh or tcsh , you must issue commands somewhat differently. You would execute the sequence just shown like this:

 shell>  setenv   VARNAME value  shell>  some_command