This is the MySQL reference manual; it documents MySQL Version 3.23.49. As MySQL is work in progress, the manual gets updated frequently. There is a very good chance that this version is out of date, unless you are looking at it online. The most recent version of this manual is available at http://www.mysql.com/documentation/ in many different formats. If you have a hard time finding information in the manual, you can try the searchable PHP version at http://www.mysql.com/documentation/manual.php.
MySQL is a very fast, multi-threaded, multi-user, and robust SQL (Structured Query Language) database server.
MySQL is free software. It is licensed with the GNU GENERAL PUBLIC LICENSE http://www.gnu.org/. See section 1.3 MySQL Licensing and Support.
The MySQL home page provides the latest information about MySQL.
The following list describes some useful sections of the manual:
IMPORTANT:
Reports of errors (often called bugs), as well as questions and comments,
should be sent to the mailing list at mysql@lists.mysql.com.
See section 1.2.22.3 How to Report Bugs or Problems.
The mysqlbug script should be used to generate bug reports.
For source distributions, the mysqlbug script can be found in the
`scripts' directory. For binary distributions, mysqlbug can
be found in the `bin' directory. If you have found a sensitive
security bug in MySQL, you should send an email to
security@mysql.com.
If you have any suggestions concerning additions or corrections to this manual, please send them to the manual team at docs@mysql.com.
This is a reference manual; it does not provide general instruction on SQL or relational database concepts. If you want general information about SQL, see section 1.2.2 General SQL Information and Tutorials. For books that focus more specifically on MySQL, see section 1.2.1 Books About MySQL.
MySQL, the most popular Open Source SQL database, is provided by MySQL AB. MySQL AB is a commercial company that builds its business providing services around the MySQL database. See section 1.1.2 What Is MySQL AB.
The official way to pronounce MySQL is ``My Ess Que Ell'' (not MY-SEQUEL). But we try to avoid correcting people who say MY-SEQUEL.
MySQL AB is the Swedish company owned and run by the MySQL founders and main developers. We are dedicated to developing MySQL and spreading our database to new users. MySQL AB owns the copyright to the MySQL server source code and the MySQL trademark. A significant amount of revenues from our services goes to developing MySQL. See section 1.1.1 What Is MySQL.
MySQL AB has been profitable providing MySQL from the start. We don't get any outside funding, but have earned all our money ourselves.
We are searching after partners that would like to support our development of MySQL so that we could accelerate the development pace. If you are interested in doing this, you can email partner@mysql.com about this!
MySQL AB has currently 20+ people (http://www.mysql.com/development/team.html) on its payroll and is growing rapidly.
Our main sources of income are:
The MySQL core values show our dedication to MySQL and Open Source.
We want MySQL to be:
MySQL AB and the people of MySQL AB:
This manual is currently available in Texinfo, plain text, Info, HTML,
PostScript, and PDF versions. The primary document is the Texinfo file.
The HTML version is produced automatically using a modified version of
texi2html. The plain text and Info versions are produced with
makeinfo. The Postscript version is produced using texi2dvi
and dvips. The PDF version is produced with pdftex.
This manual is written and maintained by David Axmark, Michael (Monty) Widenius, Jeremy Cole, and Paul DuBois. For other contributors, see section E Credits.
This manual uses certain typographical conventions:
constant
mysqladmin works, invoke it with the
--help option.''
When commands are shown that are meant to be executed by 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 command that you execute from the
mysql client program:
shell> type a shell command here mysql> type a mysql command here
Shell commands are shown using Bourne shell syntax. If you are using a
csh-style shell, you may need to issue commands slightly differently.
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
For csh, you would execute the sequence like this:
shell> setenv VARNAME value shell> some_command
Often, database, table, and column names must be substituted into commands. 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 statements may be written in uppercase or lowercase. When this manual
shows a SQL statement, uppercase is used for particular keywords if those
keywords are under discussion (to emphasize them) and lowercase is used for
the rest of the statement. For example, you might see the following in a
discussion of the SELECT statement:
mysql> SELECT count(*) FROM tbl_name;
On the other hand, in a discussion of the COUNT() function, the
same statement would be written like this:
mysql> select COUNT(*) from tbl_name;
If no particular emphasis is intended, all keywords are written uniformly in uppercase.
In syntax descriptions, square brackets (`[' and `]') are used to indicate optional words or clauses:
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}
We once started out with the intention of using mSQL to connect to our
tables using our own fast low-level (ISAM) routines. However, after some
testing we came to the conclusion that mSQL was not fast enough nor
flexible enough for our needs. This resulted in a new SQL interface to our
database but with almost the same API interface as mSQL. This API was
chosen to ease porting of third-party code.
The derivation of the name MySQL is not perfectly clear. Our base directory and a large number of our libraries and tools have had the prefix ``my'' for well over 10 years. However, Monty's daughter (some years younger) is also named My. Which of the two gave its name to MySQL is still a mystery, even for us.
The following list describes some of the important characteristics of MySQL:
FLOAT, DOUBLE, CHAR, VARCHAR,
TEXT, BLOB, DATE, TIME, DATETIME,
TIMESTAMP, YEAR, SET, and ENUM types.
See section 6.2 Column Types.
SELECT and WHERE
parts of queries. For example:
mysql> SELECT CONCAT(first_name, " ", last_name) FROM tbl_name
WHERE income/dependents > 10000 AND age > 30;
GROUP BY and ORDER BY clauses. Support
for group functions (COUNT(), COUNT(DISTINCT ...),
AVG(), STD(), SUM(), MAX() and MIN()).
LEFT OUTER JOIN and RIGHT OUTER JOIN with ANSI
SQL and ODBC syntax.
CHAR or VARCHAR field.
INSERT to insert a
subset of a table's columns; those columns that are not explicitly given
values are set to their default values.
myisamchk, a very fast utility for table checking,
optimization, and repair. All of the functionality of myisamchk
is also available through the SQL interface as well.
See section 4 MySQL Database Administration.
DELETE, INSERT, REPLACE, and UPDATE return
the number of rows that were changed (affected). It is possible to return
the number of rows matched instead by setting a flag when connecting to the
server.
ABS is a valid column name. The only restriction is that for a
function call, no spaces are allowed between the function name and the
`(' that follows it. See section 6.1.6 Is MySQL Picky About Reserved Words?.
--help or -?
options to obtain online assistance.
SHOW command can be used to retrieve
information about databases, tables, and indexes. The EXPLAIN command
can be used to determine how the optimizer resolves a query.
This section addresses the questions ``How stable is MySQL?'' and ``Can I depend on MySQL in this project?'' We will try to clarify some issues and to answer some of the more important questions that seem to concern many people. This section has been put together from information gathered from the mailing list (which is very active in reporting bugs).
At TcX, MySQL has worked without any problems in our projects since mid-1996. When MySQL was released to a wider public, we noticed that there were some pieces of ``untested code'' that were quickly found by the new users who made queries in a manner different than our own. Each new release has had fewer portability problems than the previous one (even though each has had many new features).
Each release of MySQL has been usable, and there have been problems only when users start to use code from the ``gray zones.'' Naturally, outside users don't know what the gray zones are; this section attempts to indicate those that are currently known. The descriptions deal with Version 3.23 of MySQL. All known and reported bugs are fixed in the latest version, with the exception of the bugs listed in the bugs section, which are things that are design-related. See section 1.4.7 Known errors and design deficiencies in MySQL.
MySQL is written in multiple layers and different independent modules. These modules are listed below with an indication of how well-tested each of them is:
mysql, mysqladmin, mysqlshow,
mysqldump, and mysqlimport.
fcntl()). In these cases, you should run the
MySQL daemon with the --skip-locking flag. Problems are known
to occur on some Linux systems, and on SunOS when using NFS-mounted file
systems.
fcntl() call, which is
fixed by using the --skip-locking option to
mysqld. Some people have reported lockup problems with Version 0.5.
LinuxThreads will need to be recompiled if you plan to use
1000+ concurrent connections. Although it is possible to run that many
connections with the default LinuxThreads (however, you will never go
above 1021), the default stack spacing of 2 MB makes the application
unstable, and we have been able to reproduce a coredump after creating
1021 idle connections. See section 2.6.1 Linux Notes (All Linux Versions).
SELECT statements are usually done in one time frame so there shouldn't
be a mutex locking/thread juggling.
LOAD DATA ..., INSERT ... SELECT -- Stable
ALTER TABLE -- Stable
mysqlaccess -- Stable
GRANT -- Stable
MySQL. They appear to work good and
can be used after some initial testing.
MERGE tables is still not that tested. The
other part of the MERGE code is quite well tested.
MySQL AB provides e-mail support for paying customers, but the MySQL mailing list usually provides answers to common questions. Bugs are usually fixed right away with a patch; for serious bugs, there is almost always a new release.
MySQL Version 3.22 has a 4G limit on table size. With the new
MyISAM in MySQL Version 3.23 the maximum table size is
pushed up to 8 million terabytes (2 ^ 63 bytes).
Note, however, that operating systems have their own file size limits. Here are some examples:
| Operating System | File Size Limit |
| Linux-Intel 32 bit | 2G, 4G or more, depends on Linux version |
| Linux-Alpha | 8T (?) |
| Solaris 2.5.1 | 2G (possible 4G with patch) |
| Solaris 2.6 | 4G |
| Solaris 2.7 Intel | 4G |
| Solaris 2.7 ULTRA-SPARC | 8T (?) |
On Linux 2.2 you can get bigger tables than 2G by using the LFS patch for the ext2 file system. On Linux 2.4 there exists also patches for ReiserFS to get support for big files.
This means that the table size for MySQL is normally limited by the operating system.
By default, MySQL tables have a maximum size of about 4G. You can
check the maximum table size for a table with the SHOW TABLE STATUS
command or with the myisamchk -dv table_name.
See section 4.5.5 SHOW Syntax.
If you need bigger tables than 4G (and your operating system supports
this), you should set the AVG_ROW_LENGTH and MAX_ROWS
parameter when you create your table. See section 6.5.3 CREATE TABLE Syntax. You can
also set these later with ALTER TABLE. See section 6.5.4 ALTER TABLE Syntax.
If your big table is going to be read-only, you could use
myisampack to merge and compress many tables to one.
myisampack usually compresses a table by at least 50%, so you can
have, in effect, much bigger tables. See section 4.7.4 myisampack, The MySQL Compressed Read-only Table Generator.
You can go around the operating system file limit for MyISAM data
files by using the RAID option. See section 6.5.3 CREATE TABLE Syntax.
Another solution can be the included MERGE library, which allows you to handle a collection of identical tables as one. See section 7.2 MERGE Tables.
MySQL itself has no problems with Year 2000 (Y2K) compliance:
2069; all 2-digit years are regarded to be in the range
1970 to 2069, which means that if you store 01 in a
year column, MySQL treats it as 2001.
YEAR column type
can store years 0 and 1901 to 2155 in 1 byte and display
them using 2 or 4 digits.
You may run into problems with applications that use MySQL in a
way that is not Y2K-safe. For example, many old applications store
or manipulate years using 2-digit values (which are ambiguous) rather than
4-digit values. This problem may be compounded by applications that use
values such as 00 or 99 as ``missing'' value indicators.
Unfortunately, these problems may be difficult to fix, because different applications may be written by different programmers, each of whom may use a different set of conventions and date-handling functions.
Here is a simple demonstration illustrating that MySQL doesn't have any problems with dates until the year 2030:
mysql> DROP TABLE IF EXISTS y2k;
Query OK, 0 rows affected (0.01 sec)
mysql> CREATE TABLE y2k (date date, date_time datetime, time_stamp timestamp);
Query OK, 0 rows affected (0.00 sec)
mysql> INSERT INTO y2k VALUES
-> ("1998-12-31","1998-12-31 23:59:59",19981231235959),
-> ("1999-01-01","1999-01-01 00:00:00",19990101000000),
-> ("1999-09-09","1999-09-09 23:59:59",19990909235959),
-> ("2000-01-01","2000-01-01 00:00:00",20000101000000),
-> ("2000-02-28","2000-02-28 00:00:00",20000228000000),
-> ("2000-02-29","2000-02-29 00:00:00",20000229000000),
-> ("2000-03-01","2000-03-01 00:00:00",20000301000000),
-> ("2000-12-31","2000-12-31 23:59:59",20001231235959),
-> ("2001-01-01","2001-01-01 00:00:00",20010101000000),
-> ("2004-12-31","2004-12-31 23:59:59",20041231235959),
-> ("2005-01-01","2005-01-01 00:00:00",20050101000000),
-> ("2030-01-01","2030-01-01 00:00:00",20300101000000),
-> ("2050-01-01","2050-01-01 00:00:00",20500101000000);
Query OK, 13 rows affected (0.01 sec)
Records: 13 Duplicates: 0 Warnings: 0
mysql> SELECT * FROM y2k;
+------------+---------------------+----------------+
| date | date_time | time_stamp |
+------------+---------------------+----------------+
| 1998-12-31 | 1998-12-31 23:59:59 | 19981231235959 |
| 1999-01-01 | 1999-01-01 00:00:00 | 19990101000000 |
| 1999-09-09 | 1999-09-09 23:59:59 | 19990909235959 |
| 2000-01-01 | 2000-01-01 00:00:00 | 20000101000000 |
| 2000-02-28 | 2000-02-28 00:00:00 | 20000228000000 |
| 2000-02-29 | 2000-02-29 00:00:00 | 20000229000000 |
| 2000-03-01 | 2000-03-01 00:00:00 | 20000301000000 |
| 2000-12-31 | 2000-12-31 23:59:59 | 20001231235959 |
| 2001-01-01 | 2001-01-01 00:00:00 | 20010101000000 |
| 2004-12-31 | 2004-12-31 23:59:59 | 20041231235959 |
| 2005-01-01 | 2005-01-01 00:00:00 | 20050101000000 |
| 2030-01-01 | 2030-01-01 00:00:00 | 20300101000000 |
| 2050-01-01 | 2050-01-01 00:00:00 | 00000000000000 |
+------------+---------------------+----------------+
13 rows in set (0.00 sec)
This shows that the DATE and DATETIME types will not
give any problems with future dates (they handle dates until the year
9999).
The TIMESTAMP type, which is used to store the current time, has a
range up to only 2030-01-01. TIMESTAMP has a range of
1970 to 2030 on 32-bit machines (signed value). On 64-bit
machines it handles times up to 2106 (unsigned value).
Even though MySQL is Y2K-compliant, it is your responsibility to provide unambiguous input. See section 6.2.2.1 Y2K Issues and Date Types for MySQL's rules for dealing with ambiguous date input data (data containing 2-digit year values).
For the latest book information, with user comments, please visit http://www.mysql.com/portal/books/html/index.html.
While this manual is still the right place for up to date technical information, its primary goal is to contain everything there is to know about MySQL. It is sometimes nice to have a bound book to read in bed or while you travel. Here is a list of books about MySQL and related subjects (in English).
By purchasing a book through these hyperlinks provided herein, you are contributing to the development of MySQL.
MySQL
| Available | Barnes and Noble |
| Publisher | New Riders |
| Author | Paul DuBois |
| Pub Date | 1st Edition December 1999 |
| ISBN | 0735709211 |
| Pages | 800 |
| Price | $49.99 US |
| Downloadable examples |
samp_db distribution
|
| Errata | are available here |
Foreword by Michael ``Monty'' Widenius, MySQL Moderator.
In MySQL, Paul DuBois provides you with a comprehensive guide to
one of the most popular relational database systems. Paul has
contributed to the online documentation for MySQL and is an
active member of the MySQL community. The principal MySQL
developer, Monty Widenius, and a network of his fellow developers
reviewed the manuscript, and provided Paul with the kind of insight
no one else could supply.
Instead of merely giving you a general overview of MySQL, Paul
teaches you how to make the most of its capabilities. Through two
sample database applications that run throughout the book, he
gives you solutions to problems you're sure to face. He helps you
integrate MySQL efficiently with third-party tools, such as PHP
and Perl, enabling you to generate dynamic Web pages through
database queries. He teaches you to write programs that access
MySQL databases, and also provides a comprehensive set of
references to column types, operators, functions, SQL syntax,
MySQL programming, C API, Perl DBI, and PHP API.
MySQL simply gives you the kind of information you won't find
anywhere else.
If you use MySQL, this book provides you with:
DBI and PHP APIs for developing
command-line and Web-based applications.
DBI API,
and PHP's MySQL-related functions.
MySQL & mSQL
| Available | Barnes and Noble |
| Publisher | O'Reilly |
| Authors | Randy Jay Yarger, George Reese & Tim King |
| Pub Date | 1st Edition July 1999 |
| ISBN | 1-56592-434-7, Order Number: 4347 |
| Pages | 506 |
| Price | $34.95 |
This book teaches you how to use MySQL and mSQL, two popular
and robust database products that support key subsets of SQL on both Linux
and Unix systems. Anyone who knows basic C, Java, Perl, or Python can
write a program to interact with a database, either as a stand-alone
application or through a Web page. This book takes you through the
whole process, from installation and configuration to programming
interfaces and basic administration. Includes plenty of tutorial
material.
Sams' Teach Yourself MySQL in 21 Days
| Available | Barnes and Noble |
| Publisher | Sams |
| Authors | Mark Maslakowski and Tony Butcher |
| Pub Date | June 2000 |
| ISBN | 0672319144 |
| Pages | 650 |
| Price | $39.99 |
Sams' Teach Yourself MySQL in 21 Days is for intermediate Linux users who want to move into databases. A large share of the audience is Web developers who need a database to store large amounts of information that can be retrieved via the Web.
Sams' Teach Yourself MySQL in 21 Days is a practical, step-by-step
tutorial. The reader will learn to design and employ this open source
database technology into his or her Web site using practical, hands-on
examples to follow.
E-Commerce Solutions with MySQL
| Available | Barnes and Noble |
| Publisher | Prima Communications, Inc. |
| Authors | N/A |
| Pub Date | January 2000 |
| ISBN | 0761524452 |
| Pages | 500 |
| Price | $39.99 |
No description available.
MySQL and PHP from Scratch
| Available | Barnes and Noble |
| Publisher | Que |
| Authors | N/A |
| Pub Date | September 2000 |
| ISBN | 0789724405 |
| Pages | 550 |
| Price | $34.99 |
This book puts together information on installing, setting up, and
troubleshooting Apache, MySQL, PHP3, and IMP into one complete
volume. You also learn how each piece is part of a whole by learning,
step-by-step, how to create a web-based e-mail system. Learn to run
the equivalent of Active Server Pages (ASP) using PHP3, set up an
e-commerce site using a database and the Apache web server, and create
a data entry system (such as sales, product quality tracking, customer
preferences, etc) that no installation in the PC.
Professional MySQL Programming
| Available | Barnes and Noble |
| Publisher | Wrox Press, Inc. |
| Authors | N/A |
| Pub Date | Late 2001 |
| ISBN | 1861005164 |
| Pages | 1000 |
| Price | $49.99 |
No description available.
Professional Linux Programming
| Available | Barnes and Noble |
| Publisher | Wrox Press, Inc. |
| Authors | N/A |
| Pub Date | September 2000 |
| ISBN | 1861003013 |
| Pages | 1155 |
| Price | $47.99 |
In this follow-up to the best-selling Beginning Linux Programming,
you will learn from the authors' real-world knowledge and experience of
developing software for Linux; you'll be taken through the development
of a sample 'DVD Store' application, with 'theme' chapters addressing
different aspects of its implementation. Meanwhile, individual
``take-a-break'' chapters cover important topics that go beyond the
bounds of the central theme. All focus on the practical aspects of
programming, showing how crucial it is to choose the right tools for
the job, use them as they should be used, and get things right first
time.
PHP and MySQL Web Development
| Available | Barnes and Noble |
| Publisher | Sams |
| Authors | Luke Welling, Laura Thomson |
| Pub Date | March 2001 |
| ISBN | 0672317842 |
| Pages | 700 |
| Price | $49.99 |
PHP and MySQL Web Development introduces you to the advantages
of implementing both MySQL and PHP. These advantages are detailed
through the provision of both statistics and several case studies. A
practical web application is developed throughout the book, providing
you with the tools necessary to implement a functional online
database. Each function is developed separately, allowing you the
choice to incorporate only those parts that you would like to
implement. Programming concepts of the PHP language are highlighted,
including functions which tie MySQL support into a PHP script and
advanced topics regarding table manipulation.
Books recommended by the MySQL Developers
SQL-99 Complete, Really
| Available | Barnes and Noble |
| Publisher | CMP Books |
| Authors | Peter Gulutzan, Trudy Pelzer |
| Pub Date | April 1999 |
| ISBN | 0879305681 |
| Pages | 1104 |
| Price | $55.96 |
This book contains complete descriptions of the new standards for
syntax, data structures, and retrieval processes of SQL databases. As
an example-based reference manual, it includes all of the CLI
functions, information, schema tables, and status codes, as well as a
working SQL database provided on the companion disk.
C, A reference manual
| Available | Barnes and Noble |
| Publisher | Prentice Hall |
| Authors | Samuel P. Harbison, Guy L. Steele |
| Pub Date | September 1994 |
| ISBN | 0133262243 |
| Pages | 480 |
| Price | $35.99 |
A new and improved revision of the bestselling C language
reference. This manual introduces the notion of "Clean C", writing C
code that can be compiled as a C++ program, C programming style that
emphasizes correctness, portability, maintainability, and
incorporates the ISO C Amendment 1 (1994) which specifies new
facilities for writing portable, international programs in C.
C++ for Real Programmers
| Available | Barnes and Noble |
| Publisher | Academic Press, Incorporated |
| Authors | Jeff Alger, Jim Keogh |
| Pub Date | February 1998 |
| ISBN | 0120499428 |
| Pages | 388 |
| Price | $39.95 |
C++ For Real Programmers bridges the gap between C++ as described in beginner and intermediate-level books and C++ as it is practiced by experts. Numerous valuable techniques are described, organized into three simple themes: indirection, class hierarchies, and memory management. It also provides in-depth coverage of template creation, exception handling, pointers and optimization techniques. The focus of the book is on ANSI C++ and, as such, is compiler independent.
C++ For Real Programmers is a revision of
Secrets of the C++ Masters and includes a new appendix comparing C++
with Java. The book comes with a 3.5" disk for Windows with source code.
Algorithms in C
| Available | Barnes and Noble |
| Publisher | Addison Wesley Longman, Inc. |
| Authors | Robert Sedgewick |
| Pub Date | April 1990 |
| ISBN | 0201514257 |
| Pages | 648 |
| Price | $45.75 |
Algorithms in C describes a variety of algorithms in a number of
areas of interest, including: sorting, searching, string-processing, and
geometric, graph and mathematical algorithms. The book emphasizes
fundamental techniques, providing readers with the tools to confidently
implement, run, and debug useful algorithms.
Multithreaded Programming with Pthreads
| Available | Barnes and Noble |
| Publisher | Prentice Hall |
| Authors | Bil Lewis, Daniel J. Berg |
| Pub Date | October 1997 |
| ISBN | 0136807291 |
| Pages | 432 |
| Price | $34.95 |
Based on the best-selling Threads Primer,
Multithreaded Programming with Pthreads gives you a solid
understanding of Posix threads: what they are, how they work, when to use
them, and how to optimize them. It retains the clarity and humor of
Threads Primer, but includes expanded comparisons to Win32 and OS/2
implementations. Code examples tested on all of the major UNIX platforms
are featured along with detailed explanations of how and why they use threads.
Programming the PERL DBI: Database Programming with PERL
| Available | Barnes and Noble |
| Publisher | O'Reilly & Associates, Incorporated |
| Authors | Alligator Descartes, Tim Bunce |
| Pub Date | February 2000 |
| ISBN | 1565926994 |
| Pages | 400 |
| Price | $27.96 |
Programming the Perl DBI is coauthored by Alligator Descartes, one of the most active members of the DBI community, and by Tim Bunce, the inventor of DBI. For the uninitiated, the book explains the architecture of DBI and shows you how to write DBI-based programs. For the experienced DBI dabbler, this book explains DBI's nuances and the peculiarities of each individual DBD.
The book includes:
The following book has been recommended by several people on the MySQL mailing list:
Judith S. Bowman, Sandra L. Emerson and Marcy Darnovsky The Practical SQL Handbook: Using Structured Query Language Second Edition Addison-Wesley ISBN 0-201-62623-3 http://www.awl.com
The following book has also received some recommendations by MySQL users:
Martin Gruber Understanding SQL ISBN 0-89588-644-8 Publisher Sybex 510 523 8233 Alameda, CA USA
A SQL tutorial is available on the net at http://w3.one.net/~jhoffman/sqltut.htm
Apart from the following links, you can find and download a lot of MySQL programs, tools and APIs from the Contrib directory.
1.2.4 Tutorials and Manuals
mSQL.
mSQL Tcl.
DBI/DBD.
DBI/DBD modules homepage.
There are also many Web pages that use MySQL. See section B Some MySQL Users. Send any additions to this list to webmaster@mysql.com. We now require that you show a MySQL logo somewhere if you wish your site to be added. It is okay to have it on a ``used tools'' page or something similar.
This section introduces you to the MySQL mailing lists, and gives some guidelines as to how to use them.
To subscribe to the main MySQL mailing list, send a message to the electronic mail address mysql-subscribe@lists.mysql.com.
To unsubscribe from the main MySQL mailing list, send a message to the electronic mail address mysql-unsubscribe@lists.mysql.com.
Only the address to which you send your messages is significant. The subject line and the body of the message are ignored.
If your reply address is not valid, you can specify your address
explicitly. Adding a hyphen to the subscribe or unsubscribe command
word, followed by your address with the `@' character in your
address replaced by a `='. For example, to subscribe
your_name@host.domain, send a message to
mysql-subscribe-your_name=host.domain@lists.mysql.com.
Mail to mysql-subscribe@lists.mysql.com or mysql-unsubscribe@lists.mysql.com is handled automatically by the ezmlm mailing list processor. Information about ezmlm is available at The ezmlm Website.
To post a message to the list itself, send your message to
mysql@lists.mysql.com. However, please do not send mail about
subscribing or unsubscribing to mysql@lists.mysql.com, because any
mail sent to that address is distributed automatically to thousands of other
users.
Your local site may have many subscribers to mysql@lists.mysql.com.
If so, it may have a local mailing list, so that messages sent from
lists.mysql.com to your site are propagated to the local list. In such
cases, please contact your system administrator to be added to or dropped
from the local MySQL list.
If you wish to have traffic for a mailing list go to a separate mailbox in
your mail program, set up a filter based on the message headers. You can
use either the List-ID: or Delivered-To: headers to identify
list messages.
The following MySQL mailing lists exist:
announce-subscribe@lists.mysql.com announce
mysql-subscribe@lists.mysql.com mysql
mysql-digest-subscribe@lists.mysql.com mysql-digest
mysql list in digest form. That means you get all individual
messages, sent as one large mail message once a day.
bugs-subscribe@lists.mysql.com bugs
mysqlbug script (if you are running on Windows, you should
include a description of the operating system and the MySQL version).
Preferably, you should test the problem using the latest stable or development
version of MySQL before posting! Anyone should be able to repeat the
bug by just using mysql test < script on the included test case. All
bugs posted on this list will be corrected or documented in the next
MySQL release! If there are only small code changes involved, we
will also post a patch that fixes the problem.
bugs-digest-subscribe@lists.mysql.com bugs-digest
bugs list in digest form.
internals-subscribe@lists.mysql.com internals
internals-digest-subscribe@lists.mysql.com internals-digest
internals list.
java-subscribe@lists.mysql.com java
java-digest-subscribe@lists.mysql.com java-digest
java list.
win32-subscribe@lists.mysql.com win32
win32-digest-subscribe@lists.mysql.com win32-digest
win32 list.
myodbc-subscribe@lists.mysql.com myodbc
myodbc-digest-subscribe@lists.mysql.com myodbc-digest
myodbc list.
plusplus-subscribe@lists.mysql.com plusplus
plusplus-digest-subscribe@lists.mysql.com plusplus-digest
plusplus list.
msql-mysql-modules-subscribe@lists.mysql.com msql-mysql-modules
msql-mysql-modules-digest-subscribe@lists.mysql.com msql-mysql-modules-digest
msql-mysql-modules list.
You subscribe or unsubscribe to all lists in the same way as described
above. In your subscribe or unsubscribe message, just put the appropriate
mailing list name rather than mysql. For example, to subscribe to or
unsubscribe from the myodbc list, send a message to
myodbc-subscribe@lists.mysql.com or
myodbc-unsubscribe@lists.mysql.com.
If you can't get an answer for your questions from the mailing list, one option is to pay for support from MySQL AB, which will put you in direct contact with MySQL developers. See section 1.3.5 Types of Commercial Support.
The following table shows some MySQL mailing in other languages than English. Note that these are not operated by MySQL AB, so we can't guarantee the quality on these.
mysql-france-subscribe@yahoogroups.com A French mailing list
list@tinc.net A Korean mailing list
subscribe mysql your@email.address to this list.
mysql-de-request@lists.4t2.com A German mailing list
subscribe mysql-de your@email.address to this list.
You can find information about this mailing list at
http://www.4t2.com/mysql.
mysql-br-request@listas.linkway.com.br A Portugese mailing list
subscribe mysql-br your@email.address to this list.
mysql-alta@elistas.net A Spanish mailing list
subscribe mysql your@email.address to this list.
Before posting a bug report or question, please do the following:
If you can't find an answer in the manual or the archives, check with your local MySQL expert. If you still can't find an answer to your question, go ahead and read the next section about how to send mail to mysql@lists.mysql.com.
Writing a good bug report takes patience, but doing it right the first time saves time for us and for you. A good bug report containing a full test case for the bug will make it very likely that we will fix it in the next release. This section will help you write your report correctly so that you don't waste your time doing things that may not help us much or at all.
We encourage everyone to use the mysqlbug script to generate a bug
report (or a report about any problem), if possible. mysqlbug can be
found in the `scripts' directory in the source distribution, or, for a
binary distribution, in the `bin' directory under your MySQL
installation directory. If you are unable to use mysqlbug, you should
still include all the necessary information listed in this section.
The mysqlbug script helps you generate a report by determining much
of the following information automatically, but if something important is
missing, please include it with your message! Please read this section
carefully and make sure that all the information described here is included
in your report.
The normal place to report bugs and problems is
mysql@lists.mysql.com. If you can make a test case that clearly
demonstrates the bug, you should post it to the bugs@lists.mysql.com
list. Note that on this list you should only post a full, repeatable bug
report using the mysqlbug script. If you are running on Windows,
you should include a description of the operating system and the
MySQL version. Preferably, you should test the problem using
the latest stable or development version of MySQL before
posting! Anyone should be able to repeat the bug by just using
``mysql test < script'' on the included test case or run the
shell or perl script that is included in the bug report. All bugs
posted on the bugs list will be corrected or documented in the next
MySQL release! If there are only small code changes involved
to correct this problem, we will also post a patch that fixes the
problem.
Remember that it is possible to respond to a message containing too much information, but not to one containing too little. Often people omit facts because they think they know the cause of a problem and assume that some details don't matter. A good principle is: if you are in doubt about stating something, state it! It is a thousand times faster and less troublesome to write a couple of lines more in your report than to be forced to ask again and wait for the answer because you didn't include enough information the first time.
The most common errors are that people don't indicate the version number of the MySQL distribution they are using, or don't indicate what platform they have MySQL installed on (including the platform version number). This is highly relevant information, and in 99 cases out of 100 the bug report is useless without it! Very often we get questions like, ``Why doesn't this work for me?'' then we find that the feature requested wasn't implemented in that MySQL version, or that a bug described in a report has been fixed already in newer MySQL versions. Sometimes the error is platform dependent; in such cases, it is next to impossible to fix anything without knowing the operating system and the version number of the platform.
Remember also to provide information about your compiler, if it is related to the problem. Often people find bugs in compilers and think the problem is MySQL-related. Most compilers are under development all the time and become better version by version. To determine whether or not your problem depends on your compiler, we need to know what compiler is used. Note that every compiling problem should be regarded as a bug report and reported accordingly.
It is most helpful when a good description of the problem is included in the bug report. That is, a good example of all the things you did that led to the problem and the problem itself exactly described. The best reports are those that include a full example showing how to reproduce the bug or problem. See section G.1.6 Making a test case when you experience table corruption.
If a program produces an error message, it is very important to include the message in your report! If we try to search for something from the archives using programs, it is better that the error message reported exactly matches the one that the program produces. (Even the case should be observed!) You should never try to remember what the error message was; instead, copy and paste the entire message into your report!
If you have a problem with MyODBC, you should try to generate a MyODBC trace file. See section 8.3.7 Reporting Problems with MyODBC.
Please remember that many of the people who will read your report will
do so using an 80-column display. When generating reports or examples
using the mysql command line tool, you should therefore use
the --vertical option (or the \G statement terminator)
for output that would exceed the available width for such a display
(for example, with the EXPLAIN SELECT statement; see the
example below).
Please include the following information in your report:
mysqladmin version. mysqladmin can be
found in the `bin' directory under your MySQL installation
directory.
uname -a.
mysqld died, you should also report the query that crashed
mysqld. You can usually find this out by running mysqld with
logging enabled. See section G.1.5 Using log files to find cause of errors in mysqld.
mysqldump --no-data db_name tbl_name1 tbl_name2 .... This is very easy
to do and is a powerful way to get information about any table in a database
that will help us create a situation matching the one you have.
SELECT statements, you should
always include the output of EXPLAIN SELECT ..., and at least the
number of rows that the SELECT statement produces. The more
information you give about your situation, the more likely it is that someone
can help you! For example, the following is an example of a very good bug
report (it should of course be posted with the mysqlbug script):
Example run using the mysql command line tool (note the use of the
\G statement terminator for statements whose output width would
otherwise exceed that of an 80-column display device):
mysql> SHOW VARIABLES;
mysql> SHOW COLUMNS FROM ...\G
<output from SHOW COLUMNS>
mysql> EXPLAIN SELECT ...\G
<output from EXPLAIN>
mysql> FLUSH STATUS;
mysql> SELECT ...;
<A short version of the output from SELECT,
including the time taken to run the query>
mysql> SHOW STATUS;
<output from SHOW STATUS>
mysqladmin variables extended-status processlist in your mail to
provide some information of how your system is performing!
mysqldump and create a `README' file
that describes your problem.
Create a compressed archive of your files using
tar and gzip or zip, and use ftp to transfer the
archive to ftp://support.mysql.com/pub/mysql/secret/. Then send a
short description of the problem to bugs@lists.mysql.com.
ftp to transfer it to
ftp://support.mysql.com/pub/mysql/secret/. If the data are really top
secret and you don't want to show them even to us, then go ahead and provide
an example using other names, but please regard this as the last choice.
mysqld
daemon and that you use to run any MySQL client programs. The
options to programs like mysqld and mysql, and to the
configure script, are often keys to answers and are very relevant!
It is never a bad idea to include them anyway! If you use any modules, such
as Perl or PHP, please include the version number(s) of those as well.
mysqlaccess, the output of mysqladmin reload, and all
the error messages you get when trying to connect! When you test your
privileges, you should first run mysqlaccess. After this, execute
mysqladmin reload version and try to connect with the program that
gives you trouble. mysqlaccess can be found in the `bin'
directory under your MySQL installation directory.
parse error, please check your syntax closely! If
you can't find something wrong with it, it's extremely likely that your
current version of MySQL doesn't support the query you are
using. If you are using the current version and the manual at
http://www.mysql.com/documentation/manual.php doesn't cover the
syntax you are using, MySQL doesn't support your query. In this
case, your only options are to implement the syntax yourself or e-mail
mysql-licensing@mysql.com and ask for an offer to implement it!
If the manual covers the syntax you are using, but you have an older version
of MySQL, you should check the MySQL change history to see
when the syntax was implemented. In this case, you have the option of
upgrading to a newer version of MySQL. See section F MySQL change history.
myisamchk or CHECK TABLE and
REPAIR TABLE. See section 4 MySQL Database Administration.
mysqld should NEVER crash a table if nothing killed it in the
middle of an update! If you can find the cause of mysqld dying,
it's much easier for us to provide you with a fix for the problem!
See section A.1 How to Determine What Is Causing Problems.
If you are a support customer, please cross-post the bug report to mysql-support@mysql.com for higher priority treatment, as well as to the appropriate mailing list to see if someone else has experienced (and perhaps solved) the problem.
For information on reporting bugs in MyODBC, see section 8.3.4 How to Report Problems with MyODBC.
For solutions to some common problems, see See section A Problems and Common Errors.
When answers are sent to you individually and not to the mailing list, it is considered good etiquette to summarize the answers and send the summary to the mailing list so that others may have the benefit of responses you received that helped you solve your problem!
If you consider your answer to have broad interest, you may want to post it to the mailing list instead of replying directly to the individual who asked. Try to make your answer general enough that people other than the original poster may benefit from it. When you post to the list, please make sure that your answer is not a duplication of a previous answer.
Try to summarize the essential part of the question in your reply; don't feel obliged to quote the entire original message.
Please don't post mail messages from your browser with HTML mode turned on! Many users don't read mail with a browser!
This section describes MySQL support and licensing arrangements:
The formal terms of the GPL license can be found at section K GNU GENERAL PUBLIC LICENSE. Basically, our licensing policy and interpretation of the GPL is as follows:
Note that older versions of MySQL are still using a more strict license. See the documentation for that version for more information. If you need a commercial MySQL license, because the GPL license doesn't suit your application, you can buy one at https://order.mysql.com/.
For normal internal use, MySQL costs nothing. You do not have to pay us if you do not want to.
A license is required if:
A license is NOT required if:
GNU Library General Public License. The mysql command-line
client includes code from the readline library that is under
the GPL.
For circumstances under which a MySQL license is required, you
need a license per machine that runs the mysqld server. However,
a multiple-CPU machine counts as a single machine, and there is no
restriction on the number of MySQL servers that run on one
machine, or on the number of clients concurrently connected to a server
running on that machine!
If you have any questions as to whether or not a license is required for your particular use of MySQL, please read this again and then contact us. See section 1.3.4.2 Contact Information.
If you require a MySQL license, the easiest way to pay for it is to use the license form on MySQL's secure server at https://order.mysql.com/. Other forms of payment are discussed in section 1.3.4.1 Payment information.
There are several different copyrights on the MySQL distribution:
mysqlclient library is licensed under the LGPL and
programs in the `client' directory is GPL. Each file has a header
that shows which copyright is used for that file.
getopt) library are covered
by the ``GNU LIBRARY GENERAL PUBLIC LICENSE.'' See section L GNU LESSER GENERAL PUBLIC LICENSE.
regexp library) are covered
by a Berkeley-style copyright.
readline) library
is covered by the ``GNU GENERAL PUBLIC LICENSE.'' See section K GNU GENERAL PUBLIC LICENSE.
This is also available as the file `COPYING' in the distributions.
One goal is that the SQL client library should be free enough that it is possible to add MySQL support into commercial products without a license. For this reason, we chose the LGPL license for the client code.
This means that you can use MySQL for free with any program that uses any of the free software licenses. MySQL is also free for any end user for his own or company usage.
However, if you use MySQL for something important to you, you may want to help secure its development by purchasing licenses or a support contract. See section 1.3.5 Types of Commercial Support.
Version 3.22 of MySQL is still using a more strict license. See the documentation for that version for more information.
This section describes some situations illustrating whether or not you must license the MySQL server. Generally these examples involve providing MySQL as an integral part of a product.
Note that a single MySQL license covers any number of CPUs and
mysqld servers on a machine! There is no artificial limit on the
number of clients that connect to the server in any way.
To determine whether or not you need a MySQL license when selling your application, you should ask whether the proper functioning of your application is dependent on the use of MySQL and whether you include the MySQL server with your product. There are several cases to consider:
mysqld server. For example, if you've
designed your application around MySQL, then you've really made
a commercial product that requires the engine, so you need a license.
Internet Service Providers (ISPs) often host MySQL servers for their customers. With the GPL license this does not require a license.
On the other hand, we do encourage people to use ISPs that have MySQL support, as this will give them the confidence that if they have some problem with their MySQL installation, their ISP will be able to solve the problem for them (in some cases with the help from the MySQL development team).
All ISPs that want to keep themselves up-to-date should subscribe
to our announce mailing list so that they can be aware of fatal issues
that may be relevant for their MySQL installations.
Note that if the ISP doesn't have a license for MySQL, it should give its customers at least read access to the source of the MySQL installation so that its customer can verify that it is patched correctly.
If you use MySQL in conjunction with a Web server on Unix, you don't have to pay for a license.
This is true even if you run a commercial Web server that uses MySQL, because you are not selling an embedded MySQL version yourself. However, in this case we would like you to purchase MySQL support, because MySQL is helping your enterprise.
Our current license prices are shown below. To make a purchase, please visit https://order.mysql.com/.
If you pay by credit card, the currency is EURO (European Union Euro) so the prices will differ slightly.
| Number of licenses | Per copy |
| 1-9 | 230 EURO |
| 10-24 | 138 EURO |
| 25-49 | 117 EURO |
| 50-99 | 102 EURO |
| 100-249 | 91 EURO |
| 250-499 | 76 EURO |
| 500-999 | 66 EURO |
For high volume (OEM) purchases, please contact sales@mysql.com.
For OEM purchases, you must act as the middle-man for eventual problems or extension requests from your users. We also require that OEM customers have at least an extended e-mail support contract. Note that OEM licenses only apply for products where the user doesn't have direct access to the MySQL server (embedded system). In other words, the MySQL server should only be used with the application that was supplied you.
If you have a low-margin, high-volume product, you can always talk to us about other terms (for example, a percent of the sale price). If you do, please be informative about your product, pricing, market, and any other information that may be relevant.
A full-price license is not a support agreement and includes very minimal support. This means that we try to answer any relevant questions. If the answer is in the documentation, we will direct you to the appropriate section. If you have not purchased a license or support, we probably will not answer at all.
If you discover what we consider a real bug, we are likely to fix it in any case. But if you pay for support we will notify you about the fix status instead of just fixing it in a later release.
More comprehensive support is sold separately. Descriptions of what each level of support includes are given in section 1.3.5 Types of Commercial Support. Costs for the various types of commercial support are shown below. Support level prices are in EURO (European Union Euro). One EURO is about 1.06 USD.
| Type of support | Cost per year |
| Basic e-mail support. See section 1.3.5.1 Basic E-mail Support. | EURO 200 |
| Extended e-mail support See section 1.3.5.2 Extended E-mail Support. | EURO 1000 |
| Login support See section 1.3.5.3 Login Support. | EURO 2000 |
| Extended login support See section 1.3.5.4 Extended Login Support. | EURO 5000 |
| Telephone support See section 1.3.5.5 Telephone Support. | EURO 12000 |
You may upgrade from any lower level of support to a higher level of support for the difference in price between the two support levels.
We do also provide telephone support (mostly emergency support but also 24/7 support). This support option doesn't however have a fixed price but is negotiated for case to case. If you are interested in this option you can email sales@mysql.com and tell us about your needs.
Note that as our sales staff is very busy, it may take some time until your request is handled. Our support staff does however always answer promptly to support questions!
Currently we can take SWIFT payments, checks, or credit cards.
Payment should be made to:
Postgirot Bank AB 105 06 STOCKHOLM, SWEDEN MySQL AB BOX 6434 11382 STOCKHOLM, SWEDEN SWIFT address: PGSI SESS Account number: 96 77 06 - 3
Specify: license and/or support and your name and e-mail address.
In Europe and Japan you can use EuroGiro (that should be less expensive) to the same account.
If you want to pay by check, make it payable to ``MySQL Finland AB'' and mail it to the address below:
MySQL AB BOX 6434, Torsgatan 21 11382 STOCKHOLM, SWEDEN
If you want to pay by credit card over the Internet, you can use MySQL AB's secure license form.
You can also print a copy of the license form, fill it in, and send it by fax to:
+46-8-729 69 05
If you want us to bill you, you can use the license form and write ``bill
us'' in the comment field. You can also mail a message to
sales@mysql.com (not mysql@lists.mysql.com!)
with your company information and ask us to bill you.
For commercial licensing, please contact the MySQL licensing team. The much preferred method is by e-mail to licensing@mysql.com. Fax is also possible but handling of these may take much longer (Fax +46-8-729 69 05).
If you represent a business that is interested in partnering with MySQL, please send e-mail to partner@mysql.com.
For timely, precise answers to technical questions about MySQL you should order one of our support contracts. MySQL support is provided by the MySQL developers so the standard is extremely high.
If you are interested in placing a banner advertisement on our Web site, please send e-mail to advertising@mysql.com.
If you are interested in any of the jobs listed in our jobs section, please send e-mail to jobs@mysql.com.
For general discussion amongst our many users, please direct your attention to the appropriate mailing list.
For general information inquires, please send e-mail to info@mysql.com.
For questions or comments about the workings or content of the Web site, please send e-mail to webmaster@mysql.com.
The following is true of all support options:
Basic e-mail support is a very inexpensive support option and should be thought of more as a way to support our development of MySQL than as a real support option. We at MySQL do give a lot of free support in all the different MySQL lists, and the money we get from basic e-mail support is largely used to make this possible.
At this support level, the MySQL mailing lists are the preferred means of communication. Questions normally should be mailed to the primary mailing list (mysql@lists.mysql.com) or one of the other regular lists (for example, win32@lists.mysql.com for Windows-related MySQL questions), as someone else already may have experienced and solved the problem you have. See section