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DBD-mysql-2.1012
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/ INSTALL

NAME

INSTALL - How to install and configure DBD::mysql

SYNOPSIS

perl Makefile.PL [options]
make
make test
make install

DESCRIPTION

This document describes the installation and configuration of DBD::mysql, the Perl DBI driver for the MySQL database. Before reading on, make sure that you have the prerequisites available: Perl, MySQL and DBI. For details see the separate section. "PREREQUISITES".

Depending on your version of Perl, it might be possible to use a binary distribution of DBD::mysql. If possible, this is recommended. Otherwise you need to install from the sources. If so, you will definitely need a C compiler. Installation from binaries and sources are both described in separate sections. "BINARY INSTALLATION". "SOURCE INSTALLATION".

Finally, if you encounter any problems, do not forget to read the section on known problems. "KNOWN PROBLEMS". If that doesn't help, you should look into the archive of the mailing list msql-mysql-modules@lists.mysql.com. See http://www.mysql.com for archive locations. And if that still doesn't help, please post a question on this mailing list.

PREREQUISITES

Perl

Preferrably a version of Perl, that comes preconfigured with your system. For example, all Linux and FreeBSD distributions come with Perl. For Windows, ActivePerl is recommended, see http://www.activestate.com for details.

MySQL

You need not install the actual MySQL database server, the client files and the devlopment files are sufficient. For example, the Red Hat Linux distribution comes with RPM files mysql-client and mysql-devel. These are sufficient, if the MySQL server is located on a foreign machine. You may also create client files by compiling from the MySQL source distribution and using

configure --without-server

If you are using Windows and need to compile from sources (which is only the case if you are not using ActivePerl), then you must ensure that the header and library files are installed. This may require choosing a "Custom installation" and selecting the appropriate option when running the MySQL setup program.

DBI

DBD::mysql is a DBI driver, hence you need DBI. It is available from the same source where you got the DBD::mysql distribution from.

C compiler

A C compiler is only required, if you install from source. In most cases there are binary distributions of DBD::mysql available. However, if you need a C compiler, make sure, that it is the same C compiler that was used for compiling Perl and MySQL! Otherwise you will almost definitely encounter problems because of differences in the underlying C runtime libraries.

In the worst case, this might mean to compile Perl and MySQL yourself. But believe me, experience shows that a lot of problems are fixed this way.

Gzip libraries

Late versions of MySQL come with support for compression. Thus it may be required that you have install an RPM package like libz-devel, libgz-devel or something similar.

BINARY INSTALLATION

Binary installation is possible in the most cases, depending on your system. I give some examples:

Windows

ActivePerl offers a PPM archive of DBD::mysql. All you need to do is typing

ppm
install DBI
install DBD-mysql

This will fetch the modules via HTTP and install them. If you need to use a WWW proxy server, the environment variable HTTP_proxy must be set:

set HTTP_proxy=http://my.proxy.server:8000/
ppm
install DBI
install DBD-mysql

Of course you need to replace the host name my.proxy.server and the port number 8000 with your local values.

If the above procedure doesn't work, please upgrade to the latest version of ActivePerl. Versions before build 623 are known to have problems.

Red Hat Linux

As of version 7.1, Red Hat Linux comes with MySQL and DBD::mysql. You need to ensure that the following RPM's are installed:

mysql
perl-DBI
perl-DBD-MySQL

For installation from source the following RPM's are required

mysql-devel
libz-devel

Optional are

mysql-server

Other systems

In the case of Linux or FreeBSD distributions it is very likely that all you need comes with your distribution, as in the case of Red Hat Linux. I just cannot give you names, as I am not using these systems.

Please let me know if you find the files in your SuSE Linux, Debian Linux or FreeBSD distribution so that I can extend the above list.

SOURCE INSTALLATION

So you need to install from sources. If you are lucky, the Perl module CPAN will do all for you, thanks to the excellent work of Andreas Koenig. Otherwise you will need to do a manual installation. Some of you, in particular system administrators of multiple sites, will choose automatic installation. All of these installation types have an own section. "CPAN installation". "Manual installation". "Configuration".

CPAN installation

Installation of DBD::mysql can be incredibly easy:

cpan
install DBD::mysql

If you are using the CPAN module for the first time, just answer the questions by accepting the defaults which are fine in most cases. If you are using an older version of Perl, you might instead need a

perl -MCPAN -e shell
install DBD::mysql

If you cannot get the CPAN module working, you might try manual installation. If installation with CPAN fails because the your local settings have been guessed wrong, you might try to create a script called mysql_config. This is described in more details later. "Configuration".

Manual installation

For a manual installation you need to fetch the DBD::mysql source distribution. The latest version is always available from

http://www.cpan.org/modules/by-module/DBD/

The name is typically something like

DBD-mysql-1.2216.tar.gz

The archive needs to be extracted. On Windows you may use a tool like WinZip, on Unix you type

gzip -cd DBD-mysql-1.2216.tar.gz | tar xf -

This will create a subdirectory DBD-mysql-1.2216. Enter this subdirectory and type

perl Makefile.PL
make
make test

(On Windows you may need to replace "make" with "nmake" or "dmake".) If the tests seem to look fine, you may continue with

make install

If the tests fail, you might need to configure some settings. For example you might choose a different database, the C compiler or the linker might need some flags. "Configuration". "C Compiler flags". "Linker flags".

Configuration

The install script "Makefile.PL" can be configured via a lot of switches. All switches can be used on the command line. For example, the test database:

perl Makefile.PL --testdb=<db>

If you do not like configuring these switches on the command line, you may alternatively create a script called mysql_config. This is described later on.

Available switches are:

testdb

Name of the test database, defaults to test.

testuser

Name of the test user, defaults to empty. If the name is empty, then the currently logged in users name will be used.

testpassword

Password of the test user, defaults to empty.

testhost

Host name or IP number of the test database; defaults to localhost.

testport

Port number of the test database

cflags

This is a list of flags that you want to give to the C compiler. The most important flag is the location of the MySQL header files. For example, on Red Hat Linux the header files are in /usr/include/mysql and you might try

-I/usr/include/mysql

On Windows the header files may be in C:\mysql\include and you might try

-IC:\mysql\include

The default flags are determined by running

mysql_config --cflags

More details on the C compiler flags can be found in the following section. "C Compiler flags".

libs

This is a list of flags that you want to give to the linker or loader. The most important flags are the locations and names of additional libraries. For example, on Red Hat Linux your MySQL client libraries are in /usr/lib/mysql and you might try

-L/usr/lib/mysql -lmysqlclient -lz

On Windows the libraries may be in C:\mysql\lib and

-LC:\mysql\lib -lmysqlclient

might be a good choice. The default flags are determined by running

mysql_config --libs

More details on the linker flags can be found in a separate section. "Linker flags".

If a switch is not present on the command line, then the script mysql_config will be executed. This script comes as part of the MySQL distribution. For example, to determine the C compiler flags, we are executing

mysql_config --cflags
mysql_config --libs

If you want to configure your own settings for database name, database user and so on, then you have to create a script with the same name, that replies

C Compiler flags

It is typically not so difficult to determine the appropriate flags for the C compiler. The linker flags, which you find in the next section, are another story.

The determination of the C compiler flags is usually left to a configuration script called mysql_config, which can be invoked with

mysql_config --cflags

When doing so, it will emit a line with suggested C compiler flags, for example like this:

-L/usr/include/mysql

The C compiler must find some header files. Header files have the extension .h. MySQL header files are, for example, mysql.h and mysql_version.h. In most cases the header files are not installed by default. For example, on Windows it is an installation option of the MySQL setup program (Custom installation), whether the header files are installed or not. On Red Hat Linux, you need to install an RPM archive mysql-devel or MySQL-devel.

If you know the location of the header files, then you will need to add an option

-L<header directory>

to the C compiler flags, for example -L/usr/include/mysql.

Linker flags

Appropriate linker flags are the most common source of problems while installing DBD::mysql. I will only give a rough overview, you'll find more details in the troubleshooting section. "KNOWN PROBLEMS"

The determination of the C compiler flags is usually left to a configuration script called mysql_config, which can be invoked with

mysql_config --libs

When doing so, it will emit a line with suggested C compiler flags, for example like this:

-L'/usr/lib/mysql' -lmysqlclient -lnsl -lm   -lz -lcrypt

The following items typically need to be configured for the linker:

The mysqlclient library

The MySQL client library comes as part of the MySQL distribution. Depending on your system it may be a file called

F<libmysqlclient.a>   statically linked library, Unix
F<libmysqlclient.so>  dynamically linked library, Unix
F<mysqlclient.lib>    statically linked library, Windows
F<mysqlclient.dll>    dynamically linked library, Windows

or something similar.

As in the case of the header files, the client library is typically not installed by default. On Windows you will need to select them while running the MySQL setup program (Custom installation). On Red Hat Linux an RPM archive mysql-devel or MySQL-devel must be installed.

The linker needs to know the location and name of the mysqlclient library. This can be done by adding the flags

-L<lib directory> -lmysqlclient

or by adding the complete path name. Examples:

-L/usr/lib/mysql -lmysqlclient
-LC:\mysql\lib -lmysqlclient

/usr/lib/mysql/libmysqlclient.a
C:\mysql\lib\mysqlclient.lib

The latter examples are using a statically linked library. This may be required in some cases, if the dynamically linked library is not found at run time.

The gzip library

The MySQL client can use compression when talking to the MySQL server, a nice feature when sending or receiving large texts over a slow network.

On Unix you typically find the appropriate file name by running

ldconfig -p | grep libz
ldconfig -p | grep libgz

Once you know the name (libz.a or libgz.a is best), just add it to the list of linker flags. If this seems to be causing problem you may also try to link without gzip libraries.

KNOWN PROBLEMS

1.)

Some Linux distributions don't come with a gzip library by default. Running "make" terminates with an error message like

LD_RUN_PATH="/usr/lib/mysql:/lib:/usr/lib" gcc
  -o blib/arch/auto/DBD/mysql/mysql.so  -shared
  -L/usr/local/lib dbdimp.o mysql.o -L/usr/lib/mysql
  -lmysqlclient -lm -L/usr/lib/gcc-lib/i386-redhat-linux/2.96
  -lgcc -lz 
/usr/bin/ld: cannot find -lz
collect2: ld returned 1 exit status
make: *** [blib/arch/auto/DBD/mysql/mysql.so] Error 1

If this is the case for you, install an RPM archive like libz-devel, libgz-devel, zlib-devel or gzlib-devel or something similar.

2.)

If Perl was compiled with gcc or egcs, but MySQL was compiled with another compiler or on another system, an error message like this is very likely when running "Make test":

t/00base............install_driver(mysql) failed: Can't load
'../blib/arch/auto/DBD/mysql/mysql.so' for module DBD::mysql:
../blib/arch/auto/DBD/mysql/mysql.so: undefined symbol: _umoddi3
at /usr/local/perl-5.005/lib/5.005/i586-linux-thread/DynaLoader.pm
line 168.

This means, that your linker doesn't include libgcc.a. You have the following options:

The solution is telling the linker to use libgcc. Run

gcc --print-libgcc-file

to determine the exact location of libgcc.a or for older versions of gcc

gcc -v

to determine the directory. If you know the directory, add a

-L<directory> -lgcc

to the list of C compiler flags. "Configuration". "Linker flags".

3.)

There are known problems with shared versions of libmysqlclient, at least on some Linux boxes. If you receive an error message similar to

install_driver(mysql) failed: Can't load
'/usr/lib/perl5/site_perl/i586-linux/auto/DBD/mysql/mysql.so'
for module DBD::mysql: File not found at
/usr/lib/perl5/i586-linux/5.00404/DynaLoader.pm line 166

then this error message can be misleading: It's not mysql.so that fails being loaded, but libmysqlclient.so! The usual problem is that this file is located in a directory like

/usr/lib/mysql

where the linker doesn't look for it.

The best workaround is using a statically linked mysqlclient library, for example

/usr/lib/mysql/libmysqlclient.a

You force linking against this file by replacing

-L/usr/lib/mysql -lmysqlclient

with

/usr/lib/mysql/libmysqlclient.a

in the list of linker flags. "Configuration". "Linker flags".

SUPPORT

Finally, if everything else fails, you are not alone. First of all, for an immediate answer, you should look into the archives of the mailing list msql-mysql-modules@lists.mysql.com. See http://www.mysql.com for archive locations.

If you don't find an appropriate posting and reply in the mailing list, please post a question. Typically a reply will be seen within one or two days.