NAME
DBD::mSQL / DBD::mysql - mSQL and mysql drivers for the Perl5 Database Interface (DBI)
SYNOPSIS
use DBI;
$driver = "mSQL"; # or "mSQL1";
$dsn = "DBI:$driver:database=$database;host=$hostname";
$dbh = DBI->connect($dsn, undef, undef);
or
$driver = "mysql";
$dsn = "DBI:$driver:database=$database;host=$hostname;port=$port";
$dbh = DBI->connect($dsn, $user, $password);
$drh = DBI->install_driver("mysql");
@databases = $drh->func($host, $port, 'ListDBs');
@tables = $dbh->func( 'ListTables' );
$sth = $dbh->prepare("SELECT * FROM foo WHERE bla");
or
$sth = $dbh->prepare("LISTFIELDS $table");
or
$sth = $dbh->prepare("LISTINDEX $table $index");
$sth->execute;
$numRows = $sth->rows;
$numFields = $sth->{'NUM_OF_FIELDS'};
$sth->finish;
$rc = $drh->func('createdb', $database, $host, $user, $password, 'admin');
$rc = $drh->func('dropdb', $database, $host, $user, $password, 'admin');
$rc = $drh->func('shutdown', $host, $user, $password, 'admin');
$rc = $drh->func('reload', $host, $user, $password, 'admin');
$rc = $dbh->func('createdb', $database, 'admin');
$rc = $dbh->func('dropdb', $database, 'admin');
$rc = $dbh->func('shutdown', 'admin');
$rc = $dbh->func('reload', 'admin');
EXAMPLE
#!/usr/bin/perl
use strict;
use DBI();
# Connect to the database.
my $dbh = DBI->connect("DBI:mysql:database=test;host=localhost",
"joe", "joe's password",
{'RaiseError' => 1});
# Drop table 'foo'. This may fail, if 'foo' doesn't exist.
# Thus we put an eval around it.
eval { $dbh->do("DROP TABLE foo") };
print "Dropping foo failed: $@\n" if $@;
# Create a new table 'foo'. This must not fail, thus we don't
# catch errors.
$dbh->do("CREATE TABLE foo (id INTEGER, name VARCHAR(20))");
# INSERT some data into 'foo'. We are using $dbh->quote() for
# quoting the name.
$dbh->do("INSERT INTO foo VALUES (1, " . $dbh->quote("Tim") . ")");
# Same thing, but using placeholders
$dbh->do("INSERT INTO foo VALUES (?, ?)", undef, 2, "Jochen");
# Now retrieve data from the table.
my $sth = $dbh->prepare("SELECT * FROM foo");
$sth->execute();
while (my $ref = $sth->fetchrow_hashref()) {
print "Found a row: id = $ref->{'id'}, name = $ref->{'name'}\n";
}
$sth->finish();
# Disconnect from the database.
$dbh->disconnect();
DESCRIPTION
DBD::mysql and DBD::mSQL are the Perl5 Database Interface drivers for the mysql, mSQL 1.x and mSQL 2.x databases. The drivers are part of the Msql-Mysql-modules package.
In other words: DBD::mSQL and DBD::mysql are an interface between the Perl programming language and the mSQL or mysql programming API that come with the mSQL any mysql relational database management systems. Most functions provided by the respective programming API's are supported. Some rarely used functions are missing, mainly because noone ever requested them. :-)
In what follows we first discuss the use of DBD::mysql and DBD::mSQL, because this is what you will need the most. For installation, see the sections on the INSTALLATION manpage, the WIN32 INSTALLATION entry elsewhere in this document, the KNOWN PROBLEMS entry elsewhere in this document and the KNOWN BUGS entry elsewhere in this document below. See the EXAMPLE manpage for a simple example above.
From perl you activate the interface with the statement
use DBI;
After that you can connect to multiple mSQL or MySQL database servers and send multiple queries to any of them via a simple object oriented interface. Two types of objects are available: database handles and statement handles. Perl returns a database handle to the connect method like so:
$dbh = DBI->connect("DBI:mSQL:database=$db;host=$host",
undef, undef, {RaiseError => 1});
or
$dbh = DBI->connect("DBI:mysql:database=$db;host=$host",
$user, $password, {RaiseError => 1});
Once you have connected to a database, you can can execute SQL statements with:
my $query = sprintf("INSERT INTO foo VALUES (%d, %s)",
$number, $dbh->quote("name"));
$dbh->do($query);
See the DBI(3) manpage for details on the quote and do methods. An alternative approach is
$dbh->do("INSERT INTO foo VALUES (?, ?)", undef,
$number, $name);
in which case the quote method is executed automatically. See also the bind_param method in the DBI(3) manpage. See the DATABASE HANDLES entry elsewhere in this document below for more details on database handles.
If you want to retrieve results, you need to create a so-called statement handle with:
$sth = $dbh->prepare("SELECT * FROM $table");
$sth->execute();
This statement handle can be used for multiple things. First of all you can retreive a row of data:
my $row = $sth->fetchow_hashref();
If your table has columns ID and NAME, then $row will be hash ref with keys ID and NAME. See the STATEMENT HANDLES entry elsewhere in this document below for more details on statement handles.
But now for a more formal approach:
Class Methods
connect
use DBI;
$driver = "mSQL"; # or "mSQL1"
$dsn = "DBI:$driver:$database";
$dsn = "DBI:$driver:database=$database;host=$hostname";
$dbh = DBI->connect($dsn, undef, undef);
or
$dsn = "DBI:mysql:$database";
$dsn = "DBI:mysql:database=$database;host=$hostname";
$dsn = "DBI:mysql:database=$database;host=$hostname;port=$port";
$dbh = DBI->connect($dsn, $user, $password);
A `database' must always be specified.
host
port The hostname, if not specified or specified as '', will
default to an mysql or mSQL daemon running on the local
machine on the default port for the UNIX socket.
Should the mysql or mSQL daemon be running on a non-standard
port number, you may explicitly state the port number to
connect to in the `hostname' argument, by concatenating the
hostname and port number together separated by a colon (
`:' ) character or by using the `port' argument. This
doesn't work for mSQL 2: You have to create an alternative
config file and load it using the msql_configfile attribute,
see below.
mysql_client_found_rows
Enables (TRUE value) or disables (FALSE value) the flag
CLIENT_FOUND_ROWS while connecting to the MySQL server. This
has a somewhat funny effect: Without
mysql_client_found_rows, if you perform a query like
UPDATE $table SET id = 1 WHERE id = 1
then the MySQL engine will always return 0, because no rows
have changed. With mysql_client_found_rows however, it will
return the number of rows that have an id 1, as some people
are expecting. (At least for compatibility to other
engines.)
By default this flag is disabled. However, you can enable it
by default, when installing the Msql-Mysql-modules with
perl Makefile.PL --config --mysql-use-client-found-rows
make
make install
mysql_compression
As of MySQL 3.22.3, a new feature is supported: If your DSN
contains the option "mysql_compression=1", then the
communication between client and server will be compressed.
mysql_connect_timeout
If your DSN contains the option "mysql_connect_timeout=##",
the connect request to the server will timeout if it has not
been successful after the given number of seconds.
mysql_read_default_file
mysql_read_default_group
These options can be used to read a config file like
/etc/my.cnf or ~/.my.cnf. By default MySQL's C client
library doesn't use any config files unlike the client
programs (mysql, mysqladmin, ...) that do, but outside of
the C client library. Thus you need to explicitly request
reading a config file, as in
$dsn = "DBI:mysql:test;mysql_read_default_file=/home/joe/my.cnf";
$dbh = DBI->connect($dsn, $user, $password)
The option mysql_read_default_group can be used to specify
the default group in the config file: Usually this is the
client group, but see the following example:
[perl]
host=perlhost
[client]
host=localhost
If you read this config file, then you'll be typically
connected to localhost. However, by using
$dsn = "DBI:mysql:test;mysql_read_default_group=perl;"
. "mysql_read_default_file=/home/joe/my.cnf";
$dbh = DBI->connect($dsn, $user, $password);
you'll be connected to perlhost. Note that if you specify
a default group and do not specify a file, then the default
config files will all be read. See the (missing :-)
documentation of the C function mysql_options() for details.
mysql_socket
As of MySQL 3.21.15, it is possible to choose the Unix
socket that is used for connecting to the server. This is
done, for example, with
mysql_socket=/dev/mysql
Usually there's no need for this option, unless you are
using another location for the socket than that built into
the client.
Private MetaData Methods
ListDBs
my $drh = DBI->install_driver("mysql");
@dbs = $drh->func("$hostname:$port", 'ListDBs');
@dbs = $drh->func($hostname, $port, 'ListDBs');
@dbs = $dbh->func('_ListDBs');
Returns a list of all databases managed by the mysql daemon or mSQL
daemon running on `$hostname', port `$port'. This method is rarely
needed for databases running on `localhost': You should use the
portable method
@dbs = DBI->data_sources("mysql");
or
@dbs = DBI->data_sources("mSQL");
whenever possible. It is a design problem of this method, that
there's no way of supplying a host name or port number to
`data_sources', that's the only reason why we still support
`ListDBs'. :-(
ListTables
WARNING: This method is obsolete due to DBI's $dbh->table_info().
@tables = $dbh->func('_ListTables');
Once connected to the desired database on the desired mysql or mSQL
mSQL daemon with the `DBI-'connect()> method, we may extract a list
of the tables that have been created within that database.
`ListTables' returns an array containing the names of all the tables
present within the selected database. If no tables have been
created, an empty list is returned.
@tables = $dbh->func( '_ListTables' );
foreach $table ( @tables ) {
print "Table: $table\n";
}
Server Administration
admin
$rc = $drh->func("createdb", $dbname, [host, user, password,], 'admin');
$rc = $drh->func("dropdb", $dbname, [host, user, password,], 'admin');
$rc = $drh->func("shutdown", [host, user, password,], 'admin');
$rc = $drh->func("reload", [host, user, password,], 'admin');
or
$rc = $dbh->func("createdb", $dbname, 'admin');
$rc = $dbh->func("dropdb", $dbname, 'admin');
$rc = $dbh->func("shutdown", 'admin');
$rc = $dbh->func("reload", 'admin');
For server administration you need a server connection. For
obtaining this connection you have two options: Either use a
driver handle (drh) and supply the appropriate arguments (host,
defaults localhost, user, defaults to '' and password, defaults
to ''). A driver handle can be obtained with
$drh = DBI->install_driver('mysql');
Otherwise reuse the existing connection of a database handle
(dbh).
There's only one function available for administrative purposes,
comparable to the m(y)sqladmin programs. The command being
execute depends on the first argument:
createdb
Creates the database $dbname. Equivalent to
"m(y)sqladmin create $dbname".
dropdb Drops the database $dbname. Equivalent to "m(y)sqladmin
drop $dbname".
It should be noted that database deletion is not
prompted for in any way. Nor is it undo-able from DBI.
Once you issue the dropDB() method, the database will be gone!
These method should be used at your own risk.
shutdown
Silently shuts down the database engine. (Without
prompting!) Equivalent to "m(y)sqladmin shutdown".
reload Reloads the servers configuration files and/or tables.
This can be particularly important if you modify access
privileges or create new users.
DATABASE HANDLES
The DBD::mysql driver supports the following attributes of database
handles (read only):
$infoString = $dbh->{'info'};
$threadId = $dbh->{'thread_id'};
$insertId = $dbh->{'mysql_insertid'}
These correspond to mysql_info(), mysql_thread_id() and
mysql_insertid(), respectively.
STATEMENT HANDLES
The statement handles of DBD::mysql and DBD::mSQL support a number
of attributes. You access these by using, for example,
my $numFields = $sth->{'NUM_OF_FIELDS'};
Note, that most attributes are valid only after a successfull
execute. An `undef' value will returned in that case. The most
important exception is the `mysql_use_result' attribute: This forces
the driver to use mysql_use_result rather than mysql_store_result.
The former is faster and less memory consuming, but tends to block
other processes. (That's why mysql_store_result is the default.)
To set the `mysql_use_result' attribute, use either of the
following:
my $sth = $dbh->prepare("QUERY", { "mysql_use_result" => 1});
or
my $sth = $dbh->prepare("QUERY");
$sth->{"mysql_use_result"} = 1;
Column dependent attributes, for example NAME, the column names,
are returned as a reference to an array. The array indices are
corresponding to the indices of the arrays returned by fetchrow
and similar methods. For example the following code will print a
header of table names together with all rows:
my $sth = $dbh->prepare("SELECT * FROM $table");
if (!$sth) {
die "Error:" . $dbh->errstr . "\n";
}
if (!$sth->execute) {
die "Error:" . $sth->errstr . "\n";
}
my $names = $sth->{'NAME'};
my $numFields = $sth->{'NUM_OF_FIELDS'};
for (my $i = 0; $i < $numFields; $i++) {
printf("%s%s", $$names[$i], $i ? "," : "");
}
print "\n";
while (my $ref = $sth->fetchrow_arrayref) {
for (my $i = 0; $i < $numFields; $i++) {
printf("%s%s", $$ref[$i], $i ? "," : "");
}
print "\n";
}
For portable applications you should restrict yourself to attributes
with capitalized or mixed case names. Lower case attribute names are
private to DBD::mSQL and DBD::mysql. The attribute list includes:
ChopBlanks
this attribute determines whether a fetchrow will chop
preceding and trailing blanks off the column values. Chopping
blanks does not have impact on the max_length attribute.
mysql_insertid
MySQL has the ability to choose unique key values automatically.
If this happened, the new ID will be stored in this attribute.
This attribute is not valid for DBD::mSQL. An alternative way
for accessing this attribute is via $dbh->{'mysql_insertid'}.
(Note we are using the $dbh in this case!)
mysql_is_blob
Reference to an array of boolean values; TRUE indicates, that
the respective column is a blob. This attribute is valid for
MySQL only.
mysql_is_key
Reference to an array of boolean values; TRUE indicates, that
the respective column is a key. This is valid for MySQL only.
mysql_is_num
Reference to an array of boolean values; TRUE indicates, that
the respective column contains numeric values.
mysql_is_pri_key
Reference to an array of boolean values; TRUE indicates, that
the respective column is a primary key. This is only valid for
MySQL and mSQL 1.0.x: mSQL 2.x uses indices.
mysql_length
mysql_max_length
A reference to an array of maximum column sizes. The
max_length is the maximum physically present in the result
table, length gives the theoretically possible maximum.
max_length is valid for MySQL only.
NAME
A reference to an array of column names.
NULLABLE
A reference to an array of boolean values; TRUE indicates that
this column may contain NULL's.
NUM_OF_FIELDS
Number of fields returned by a SELECT or LISTFIELDS
statement. You may use this for checking whether a statement
returned a result: A zero value indicates a non-SELECT statement
like INSERT, DELETE or UPDATE.
mysql_table
A reference to an array of table names, useful in a JOIN
result.
TYPE
A reference to an array of column types. The engine's native
column types are mapped to portable types like
DBI::SQL_INTEGER() or DBI::SQL_VARCHAR(), as good as possible.
Not all native types have a meaningfull equivalent, for example
DBD::mSQL::IDX_TYPE() or DBD::mysql::FIELD_TYPE_INTERVAL are
mapped to DBI::SQL_VARCHAR(). If you need the native column
types, use mysql_type or msql_type, respectively. See below.
mysql_type
A reference to an array of MySQL's native column types, for
example DBD::mysql::FIELD_TYPE_SHORT() or
DBD::mysql::FIELD_TYPE_STRING(). Use the TYPE attribute, if
you want portable types like DBI::SQL_SMALLINT() or
DBI::SQL_VARCHAR().
mysql_type_name
Similar to mysql, but type names and not numbers are returned.
Whenever possible, the ANSI SQL name is preferred.
TRANSACTION SUPPORT
Beginning with Msql-Mysql-modules 1.2216, transactions are supported
by DBD::mysql. The transaction support works as follows:
* By default AutoCommit mode is on, following the DBI
specifications.
* If you execute
$dbh-E<gt>{'AutoCommit'} = 0;
or
$dbh-E<gt>{'AutoCommit'} = 1;
then the driver will set the MySQL server variable autocommit to
0 or 1, respectively. Switching from 0 to 1 will also issue a
COMMIT, following the DBI specifications.
* The methods
$dbh-E<gt>rollback();
$dbh-E<gt>commit();
will issue the commands COMMIT and ROLLBACK, respectively. A
ROLLBACK will also be issued if AutoCommit mode is off and the
database handles DESTROY method is called. Again, this is
following the DBI specifications.
Given the above, you should note the following:
* You should never change the server variable autocommit manually,
unless you are ignoring DBI's transaction support.
* Switching AutoCommit mode from on to off or vice versa may fail.
You should always check for errors, when changing AutoCommit
mode. The suggested way of doing so is using the DBI flag
RaiseError. If you don't like RaiseError, you have to use code
like the following:
$dbh->{'AutoCommit'} = 0;
if ($dbh->{'AutoCommit'}) {
# An error occurred!
}
* If you detect an error while changing the AutoCommit mode, you
should no longer use the database handle. In other words, you
should disconnect and reconnect again, because the transaction
mode is unpredictable. Alternatively you may verify the
transaction mode by checking the value of the server variable
autocommit. However, such behaviour isn't portable.
SQL EXTENSIONS
Certain metadata functions of mSQL and mysql that are available on
the C API level, haven't been implemented here. Instead they are
implemented as "SQL extensions" because they return in fact nothing
else but the equivalent of a statement handle. These are:
LISTFIELDS $table
Returns a statement handle that describes the columns of $table.
Ses the docs of msqlListFields or mysql_list_fields (C API) for
details.
LISTINDEX $table $index
mSQL only; returns a statement handle that describes the index
$index of table $table. See the docs of msqlListIndex for
details.
COMPATIBILITY ALERT
The statement attribute TYPE has changed its meaning, as of
Msql-Mysql-modules 1.19_19. Formerly it used to be the an array of
native engine's column types, but it is now an array of portable SQL
column types. The old attribute is still available as mysql_type
or msql_type, respectively.
The Msql-Mysql-modules are a moving target, due to a number of
reasons:
- Of course they have to conform the DBI guidelines and
developments.
- They have to keep track with the latest MySQL developments.
- And, surprisingly, they have to be as close to ODBC as
possible: This is due to the current direction of DBI.
- And, last not least, as any tool they have a little bit of
own life.
This means that a lot of things had to and have to be changed. As I
am not interested in maintaining a lot of compatibility kludges,
which only increase the drivers code without being really usefull, I
did and will remove some features, methods or attributes.
To ensure a smooth upgrade, the following policy will be applied:
Obsolete features
The first step is to declare something obsolete. This means,
that no code is changed, but the feature appears in the list
of obsolete features. See the Obsolete Features entry
elsewhere in this document below.
Deprecated features
If the feature has been obsolete for quite some time,
typically in the next major stable release, warnings will be
inserted in the code. You can suppress these warnings by
setting
$DBD::mysql = 1;
In the docs the feature will be moved from the list of
obsolete features to the list of deprecated features. See
the Deprecated Features entry elsewhere in this document
below.
Removing features
Finally features will be removed silently in the next major
stable release. The feature will be shown in the list of
historic features. See the Historic Features entry elsewhere
in this document below.
Example: The statement handle attribute
$sth->{'LENGTH'}
was declared obsolete in Msql-Mysql-modules 1.18xy. It is considered
deprecated in Msql-Mysql-modules 1.20xy (current as of this writing)
and will finally be removed in Msql-Mysql-modules 1.22xy.
Obsolete Features
_ListTables
This method is obsoleted by DBI's new method
$dbh->tables()
See also $dbh->table_info(). Portable applications will prefer
@tables = map { $_ =~ s/.*\.//; $_ } $dbh->tables()
because, depending on the engine, the string "user.table" will
be returned, user being the table owner. The method will be
deprecated in 1.23_xy and 1.24xy and removed in 1.25_xy and
1.26xy.
Deprecated Features
_InsertID
The method
$dbh->func('_InsertID');
can be replaced with
$dbh->{'mysql_insertid'};
The method is deprecated as of 1.21_xy, thus it will be removed
in 1.23_xy and 1.24xy.
Statement handle attributes:
affected_rows
IS_PRI_KEY
is_pri_key
IS_NOT_NULL
is_not_null
IS_KEY
is_key
IS_BLOB
is_blob
IS_NUM
is_num
LENGTH
length
MAXLENGTH
maxlength
NUMROWS
numrows
NUMFIELDS
numfields
RESULT
result
TABLE
table
format_max_size
format_default_size
format_type_name
All of the above statement handle attributes are not conforming
to DBI's naming conventions, thus they have been declared
deprecated in 1.20xy. However, I forgot to insert warnings in
the driver. These warnings have been inserted in 1.21_07, thus
the attributes will be removed in 1.23_xy and 1.24xy.
In most of the above cases the driver name has been added and
the resulting name was lowercased. For example, you use
$sth->{'mysql_is_num'};
now. IS_NOT_NULL can be replaced with NULLABLE (note you need to
invert the logical value!), LENGTH, format_max_size and
format_default_size will be dropped in favour of PRECISION,
affected_rows and NUMROWS are identical with
$sth->rows();
and NUMFIELDS is the same as NUM_OF_FIELDS. Finally
format_right_justify is the same as mysql_type_name.
Historic Features
_CreateDB
_DropDB The methods
$dbh->func($db, 'CreateDB');
$dbh->func($db, 'DropDB');
have been used for creating or dropping databases. They have
been removed in 1.21_07 in favour of
$drh->func("createdb", $dbname, $host, "admin")
$drh->func("dropdb", $dbname, $host, "admin")
_ListFields
The method
$sth = $dbh->func($table, '_ListFields');
has been used to list a tables columns names, types and other
attributes. This method has been removed in 1.21_07 in favour of
$sth = $dbh->prepare("LISTFIELDS $table");
_ListSelectedFields
The method
$sth->func('_ListSelectedFields');
use to return a hash ref of attributes like 'IS_NUM', 'IS_KEY'
and so on. These attributes are now accessible via
$sth->{'mysql_is_num'};
$sth->{'mysql_is_key'};
and so on. Thus the method has been removed in 1.21_07.
_NumRows
The method
$sth->func('_NumRows');
used to be equivalent to
$sth->rows();
and has been removed in 1.21_07.
MULTITHREADING
The multithreading capabilities of the Msql-Mysql-modules depend completely on the underlying C libraries: The modules are working with handle data only, no global variables are accessed or (to the best of my knowledge) thread unsafe functions are called. Thus DBD::mSQL and DBD::mysql are completely thread safe, if the C libraries thread safe and you don't share handles among threads.
The obvious questions is: Are the C libraries thread safe? In the case of mSQL the answer is definitely "no". The C library has a concept of one single active connection at a time and that is not what threads like.
In the case of MySQL the answer is "mostly" and, in theory, you should be able to get a "yes", if the C library is compiled for being thread safe (By default it isn't.) by passing the option -with-thread-safe-client to configure. See the section on How to make a threadsafe client in the manual.
INSTALLATION
Windows users may skip this section and pass over to the WIN32 INSTALLATION entry elsewhere in this document below. Others, go on reading.
First of all, you do not need an installed MySQL server for installing DBD::mSQL and/or DBD::mysql. However, you need at least the client libraries and possibly the header files, if you are compiling DBD::mysql or DBD::mSQL from source. In the case of MySQL you can create a client-only version by using the configure option --without-server. If you are using precompiled binaries, then it may be possible to use just selected RPM's like MySQL-client and MySQL-devel or something similar, depending on the distribution.
First you need to install the DBI module. For using dbimon, a simple DBI shell it is recommended to install Data::ShowTable another Perl module.
I recommend trying automatic installation via the CPAN module. Try
perl -MCPAN -e shell
If you are using the CPAN module for the first time, it will prompt you a lot of questions. If you finally receive the CPAN prompt, enter
install Bundle::DBD::mSQL
or
install Bundle::DBD::mysql
If this fails (which may be the case for a number of reasons, for example because you are behind a firewall or don't have network access), you need to do a manual installation. First of all you need to fetch the archives from any CPAN mirror, for example
ftp://ftp.funet.fi/pub/languages/perl/CPAN/modules/by-module
The following archives are required (version numbers may have changed, I choose those which are current as of this writing):
DBI/DBI-1.13.tar.gz
Data/Data-ShowTable-3.3.tar.gz
DBD/Msql-Mysql-modules-1.2217.tar.gz
Then enter the following commands:
gzip -cd DBI-1.13.tar.gz | tar xf -
cd DBI-1.13
perl Makefile.PL
make
make test
make install
cd ..
gzip -cd Data-ShowTable-3.3.tar.gz | tar xf -
cd Data-ShowTable-3.3
perl Makefile.PL
make
make install # Don't try make test, the test suite is broken
cd ..
gzip -cd Msql-Mysql-modules-1.2217.tar.gz | tar xf -
cd Msql-Mysql-modules-1.2217
perl Makefile.PL
make
make test
make install
During "perl Makefile.PL" you will be prompted some questions. In particular you have to choose the installed drivers (MySQL, mSQL2 and/or mSQL1). The MySQL driver will be called DBD::mysql, a single mSQL driver will be called DBD::mSQL. If you want to support both mSQL1 and mSQL2, they former will be DBD::mSQL1.
Other questions are the directories with header files and libraries. For example, of your file mysql.h is in /usr/include/mysql/mysql.h, then enter the header directory /usr, likewise for /usr/lib/mysql/libmysqlclient.a or /usr/lib/libmysqlclient.so. For mSQL go looking for msql.h (typically in /usr/include/msql.h and libmsql.a (probably in /usr/lib/libmsql.a).
See the the KNOWN PROBLEMS entry elsewhere in this document section below if you encounter any problems within "make" or "make test".
WIN32 INSTALLATION
I have never attempted to install DBD::mSQL under Win32, so this is only for MySQL. If anyone succeeds, please let me know what you did.
If you are using ActivePerl, you may use ppm to install DBD-mysql. For Perl 5.6, upgrade to Build 623 or later, then it is sufficient to run
ppm install DBI
ppm install DBD::mysql
The same applied to Perl 5.005.
Otherwise you definitely need a C compiler. And it must be the same compiler that was being used for compiling Perl itself. If you don't have a C compiler, the file README.win32 from the Perl source distribution tells you where to obtain freely distributable C compilers like egcs or gcc. The Perl sources are available on any CPAN mirror in the src directory, for example
ftp://ftp.funet.fi/pub/languages/perl/CPAN/src/latest.tar.gz
I recommend using the win32clients package for installing DBD::mysql under Win32, available for download on www.tcx.se. The following steps have been required for me:
*** c:\Perl\lib\ExtUtils\Liblist.pm.orig Sat Apr 15 20:03:40 2000
--- c:\Perl\lib\ExtUtils\Liblist.pm Sat Apr 15 20:03:45 2000
***************
*** 230,235 ****
--- 230,239 ----
# add "$Config{installarchlib}/CORE" to default search path
push @libpath, "$Config{installarchlib}/CORE";
+ if ($VC and exists($ENV{LIB}) and defined($ENV{LIB})) {
+ push(@libpath, split(/;/, $ENV{LIB}));
+ }
+
foreach (Text::ParseWords::quotewords('\s+', 0, $potential_libs)){
$thislib = $_;
- Extract sources into C:\. This will create a directory C:\mysql
with subdirectories include and lib.
IMPORTANT: Make sure this subdirectory is not shared by other
TCX files! In particular do not store the MySQL server in the
same directory. If the server is already installed in C:\mysql,
choose a location like C:\tmp, extract the win32clients there.
Note that you can remove this directory entirely once you have
installed the Msql-Mysql-modules.
- Extract the Msql-Mysql-modules sources into another directory,
for example C:\src\siteperl
- Open a DOS shell and change directory to C:\src\siteperl.
- The next step is only required if you repeat building the
modules: Make sure that you have a clean build tree by running
nmake realclean
If you don't have VC++, replace nmake with your flavour of make.
If error messages are reported in this step, you may safely
ignore them.
- Run
perl Makefile.PL
which will prompt you for some settings. The really important
ones are:
Which DBMS do you want to use?
enter a 1 here (MySQL only), and
Where is your mysql installed? Please tell me the directory that
contains the subdir include.
where you have to enter the win32clients directory, for example
C:\mysql or C:\tmp\mysql.
- Continued in the usual way:
nmake
nmake install
See the first section of the KNOWN PROBLEMS entry elsewhere in this document below.
If you want to create a PPM package for the ActiveState Perl version, then modify the above steps as follows: Run
perl Makefile.PL NAME=DBD-mysql BINARY_LOCATION=DBD-mysql.tar.gz
nmake ppd
nmake
Once that is done, use tar and gzip (for example those from the CygWin32 distribution) to create an archive:
mkdir x86
tar cf x86/DBD-mysql.tar blib
gzip x86/DBD-mysql.tar
Put the files x86/DBD-mysql.tar.gz and DBD-mysql.ppd onto some WWW server and install them by typing
install http://your.server.name/your/directory/DBD-mysql.ppd
in the PPM program.
KNOWN PROBLEMS
1.) If the MySQL binaries are compiled with gcc or egcs (as the
precompiled binaries are), but your Perl is using another
compiler, it is likely that you receive an error message like
the following 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:
a) Either recompile Perl or Mysql, it doesn't matter
which. The important thing is that you use the same
compiler for both. This is definitely the
recommended solution in the long term.
b) A simple workaround is to include libgcc.a manually.
Do a "make clean" and "make" and in the output wait
for a line like
LD_RUN_PATH="/usr/lib/mysql:/lib" egcs -o
../blib/arch/auto/DBD/mysql/mysql.so -shared -L/usr/local/lib
dbdimp.o mysql.o -L/usr/lib/mysql -L/usr/lib/mysql -lmysqlclient
-lm
Repeat the same line in the shell by adding
-L/usr/lib/gcc-lib/i386-redhat-linux/gcc-2.7.2.3 -lgcc
where the directory is the location of libgcc.a. The
best choice for locating this file is executing
gcc --print-libgcc-file
or
gcc -v
2.) 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!
As a workaround, recompile the Msql-Mysql-modules with
perl Makefile.PL --static --config
make
make test
make install
This option forces linkage against the static libmysqlclient.a.
3.) By default mSQL2 is installed to allow local access only. This
can break the test scripts akmisc.t, msql1.t and msql2.t. You
might notice a message like
t/akmisc............Can't connect to MSQL server on localhost at
t/akmisc.t line 131
Cannot connect: Can't connect to MSQL server on localhost
It looks as if your server (on localhost) is not up and running.
This test requires a running server.
Please make sure your server is running and retry.
dubious
Test returned status 10 (wstat 2560, 0xa00)
If this is the case, try to change the value of "Remote_Access"
in your msql.conf file to "True". If the value was set
intentionally, you might restore the old value after the tests
ran ok.
4.) If linking fails under Win32 because of a missing symbol
pthread_cond_init, apply the following patch to dbd/dbdimp.c:
*** dbd/dbdimp.c.orig Wed Sep 23 14:39:33 1998
--- dbd/dbdimp.c Fri Oct 02 10:37:16 1998
***************
*** 1708,1712 ****
--- 1709,1720 ----
}
return TRUE;
}
+
+ #if !defined(UNIX) && defined(WIN32)
+ int pthread_cond_init()
+ {
+ return 0;
+ }
+ #endif
#endif
(I could make this part of the source distribution, but I think
this is an ugly hack and hopefully Monty will fix the missing
symbol in the next release of MyODBC.)
5.) mSQL 2.0.4 had a bug, that caused the test t/40bindparam.t to
fail. This bug is fixed in later versions, 2.0.6 and higher.
6.) From time to time compiling DBD::mSQL fails with messages like
In file included from ../dbd/myMsql.h:55,
from ../dbd/dbdimp.h:32,
from dbdimp.c:29:
/usr/local/Hughes/include/common/portability.h:74:
redefinition of `u_int'
/usr/include/sys/types.h:52: `u_int' previously declared here
/usr/local/Hughes/include/common/portability.h:78: redefinition of
`ssize_t'
/usr/include/sys/types.h:116: `ssize_t' previously declared here
*** Error code 1
A workaroud is using
perl Makefile.PL --config DEFINE="-DHAVE_SSIZE_T -DHAVEUINT"
KNOWN BUGS
The port part of the first argument to the connect call is implemented in an unsafe way when using mSQL. In fact it is just setting the environment variable MSQL_TCP_PORT during the connect call. If another connect call uses another port and the handles are used simultaneously, they will interfere. I doubt that this will ever change.
AUTHORS
The current versions of DBD::mSQL and DBD::mysql is almost completely written by Jochen Wiedmann (joe@ispsoft.de). The first version's author was Alligator Descartes(descarte@symbolstone.org), who has been aided and abetted by Gary Shea, Andreas König and Tim Bunce amongst others.
The Msql and Mysql modules have originally been written by Andreas König <koenig@kulturbox.de>. The current version, mainly an emulation layer, is from Jochen Wiedmann.
COPYRIGHT
This module is Copyright (c) 1997-1999 Jochen Wiedmann, with code portions Copyright (c)1994-1997 their original authors. This module is released under the same license as Perl itself. See the Perl README for details.
MAILING LIST SUPPORT
MAILING LIST SUPPORT
This module is maintained and supported on a mailing list,
msql-mysql-modules@lists.mysql.com
To subscribe to this list, send a mail to
msql-mysql-modules-subscribe@lists.mysql.com
or
msql-mysql-modules-digest-subscribe@lists.mysql.com
Mailing list archives are available at
http://www.progressive-comp.com/Lists/?l=msql-mysql-modules
Additionally you might try the dbi-user mailing list for questions about DBI and its modules in general. Subscribe via
Mailing list archives are at
http://www.rosat.mpe-garching.mpg.de/mailing-lists/PerlDB-Interest/
http://outside.organic.com/mail-archives/dbi-users/
http://www.coe.missouri.edu/~faq/lists/dbi.html
ADDITIONAL DBI INFORMATION
Additional information on the DBI project can be found on the World Wide Web at the following URL:
http://www.symbolstone.org/technology/perl/DBI
where documentation, pointers to the mailing lists and mailing list archives and pointers to the most current versions of the modules can be used.
Information on the DBI interface itself can be gained by typing:
perldoc DBI
right now!