Table of Contents
The Perl DBI module provides a generic interface
for database access. You can write a DBI script
that works with many different database engines without change. To
use DBI, you must install the
DBI module, as well as a DataBase Driver (DBD)
module for each type of database server you want to access. For
MySQL, this driver is the DBD::mysql module.
Perl, and the DBD::MySQL module for
DBI must be installed if you want to run the
MySQL benchmark scripts; see The MySQL Benchmark Suite.
Perl support is not included with MySQL distributions. You can obtain the necessary modules from http://search.cpan.org for Unix, or by using the ActiveState ppm program on Windows. The following sections describe how to do this.
The DBI/DBD interface requires
Perl 5.6.0, and 5.6.1 or later is preferred. DBI does not
work if you have an older version of Perl. You should use
DBD::mysql 4.009 or higher. Although earlier
versions are available, they do not support the full functionality
of MySQL 5.6.
MySQL Perl support requires that you have installed MySQL client programming support (libraries and header files). Most installation methods install the necessary files. If you install MySQL from RPM files on Linux, be sure to install the developer RPM as well. The client programs are in the client RPM, but client programming support is in the developer RPM.
The files you need for Perl support can be obtained from the CPAN (Comprehensive Perl Archive Network) at http://search.cpan.org.
The easiest way to install Perl modules on Unix is to use the
CPAN module. For example:
shell>perl -MCPAN -e shellcpan>install DBIcpan>install DBD::mysql
The DBD::mysql installation runs a number of
tests. These tests attempt to connect to the local MySQL server
using the default user name and password. (The default user name
is your login name on Unix, and ODBC on
Windows. The default password is “no password.”) If
you cannot connect to the server with those values (for example,
if your account has a password), the tests fail. You can use
force install DBD::mysql to ignore the failed
tests.
DBI requires the
Data::Dumper module. It may be installed; if
not, you should install it before installing
DBI.
It is also possible to download the module distributions in the form of compressed tar archives and build the modules manually. For example, to unpack and build a DBI distribution, use a procedure such as this:
Unpack the distribution into the current directory:
shell> gunzip < DBI-VERSION.tar.gz | tar xvf -
This command creates a directory named
DBI-.
VERSION
Change location into the top-level directory of the unpacked distribution:
shell> cd DBI-VERSION
Build the distribution and compile everything:
shell>perl Makefile.PLshell>makeshell>make testshell>make install
The make test command is important because it
verifies that the module is working. Note that when you run that
command during the DBD::mysql installation to
exercise the interface code, the MySQL server must be running or
the test fails.
It is a good idea to rebuild and reinstall the
DBD::mysql distribution whenever you install a
new release of MySQL. This ensures that the latest versions of the
MySQL client libraries are installed correctly.
If you do not have access rights to install Perl modules in the system directory or if you want to install local Perl modules, the following reference may be useful: http://learn.perl.org/faq/perlfaq8.html#How-do-I-keep-my-own-module-library-directory-
On Windows, you should do the following to install the MySQL
DBD module with ActiveState Perl:
Get ActiveState Perl from http://www.activestate.com/Products/ActivePerl/ and install it.
Open a console window.
If necessary, set the HTTP_proxy variable.
For example, you might try a setting like this:
C:\> set HTTP_proxy=my.proxy.com:3128
Start the PPM program:
C:\> C:\perl\bin\ppm.pl
If you have not previously done so, install
DBI:
ppm> install DBI
If this succeeds, run the following command:
ppm> install DBD-mysql
This procedure should work with ActiveState Perl 5.6 or higher.
If you cannot get the procedure to work, you should install the ODBC driver instead and connect to the MySQL server through ODBC:
use DBI;
$dbh= DBI->connect("DBI:ODBC:$dsn",$user,$password) ||
die "Got error $DBI::errstr when connecting to $dsn\n";
If Perl reports that it cannot find the
../mysql/mysql.so module, the problem is
probably that Perl cannot locate the
libmysqlclient.so shared library. You should
be able to fix this problem by one of the following methods:
Copy libmysqlclient.so to the directory
where your other shared libraries are located (probably
/usr/lib or /lib).
Modify the -L options used to compile
DBD::mysql to reflect the actual location
of libmysqlclient.so.
On Linux, you can add the path name of the directory where
libmysqlclient.so is located to the
/etc/ld.so.conf file.
Add the path name of the directory where
libmysqlclient.so is located to the
LD_RUN_PATH environment variable. Some
systems use LD_LIBRARY_PATH instead.
You may also need to modify the -L options if
there are other libraries that the linker fails to find. For
example, if the linker cannot find libc because
it is in /lib and the link command specifies
-L/usr/lib, change the -L option
to -L/lib or add -L/lib to the
existing link command.
If you get the following errors from
DBD::mysql, you are probably using
gcc (or using an old binary compiled with
gcc):
/usr/bin/perl: can't resolve symbol '__moddi3' /usr/bin/perl: can't resolve symbol '__divdi3'
Add -L/usr/lib/gcc-lib/... -lgcc to the link
command when the mysql.so library gets built
(check the output from make for
mysql.so when you compile the Perl client).
The -L option should specify the path name of the
directory where libgcc.a is located on your
system.
Another cause of this problem may be that Perl and MySQL are not both compiled with gcc. In this case, you can solve the mismatch by compiling both with gcc.