/usr/man/cat.3/DBD__mysql.3.Z
NAME
DBD::mysql - MySQL driver for the Perl5 Database Interface (DBI)
SYNOPSIS
use DBI;
$dsn = "DBI:mysql:database=$database;host=$hostname;port=$port";
$dbh = DBI->connect($dsn, $user, $password);
$drh = DBI->install_driver("mysql");
@databases = DBI->data_sources("mysql");
or
@databases = DBI->data_sources("mysql",
{"host" => $host, "port" => $port});
$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 is the Perl5 Database Interface driver for the MySQL data-
base. In other words: DBD::mysql is an interface between the Perl pro-
gramming language and the MySQL programming API that comes with the
MySQL relational database management system. Most functions provided by
this programming API 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, because this is
what you will need the most. For installation, see the sections on
INSTALLATION, "WIN32 INSTALLATION", and "KNOWN BUGS" below. See EXAMPLE
for a simple example above.
From perl you activate the interface with the statement
use DBI;
After that you can connect to multiple 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 han-
dles. Perl returns a database handle to the connect method like so:
$dbh = DBI->connect("DBI:mysql:database=$db;host=$host",
$user, $password, {RaiseError => 1});
Once you have connected to a database, you can can execute SQL state-
ments with:
my $query = sprintf("INSERT INTO foo VALUES (%d, %s)",
$number, $dbh->quote("name"));
$dbh->do($query);
See DBI(3) 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 DBI(3). See "DATABASE HANDLES" below for more
details on database handles.
If you want to retrieve results, you need to create a so-called state-
ment 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 "STATEMENT HANDLES" below for more details on
statement handles.
But now for a more formal approach:
Class Methods
connect
use DBI;
$dsn = "DBI:mysql:$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 daemon running on the local machine on the default
port for the UNIX socket.
Should the MySQL daemon be running on a non-standard port num-
ber, 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.
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.)
mysql_compression
As of MySQL 3.22.3, a new feature is supported: If your DSN
contains the option "mysql_compression=1", then the communica-
tion 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:
[client]
host=localhost
[perl]
host=perlhost
(Note the order of the entries! The example won't work, if you
reverse the [client] and [perl] sections!)
If you read this config file, then you'll be typically con-
nected 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 con-
fig files will all be read. See the 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.
mysql_ssl
A true value turns on the CLIENT_SSL flag when connecting to
the MySQL database:
mysql_ssl=1
This means that your communication with the server will be
encrypted.
If you turn mysql_ssl on, you might also wish to use the fol-
lowing flags:
mysql_ssl_client_key
mysql_ssl_client_cert
mysql_ssl_ca_file
mysql_ssl_ca_path
mysql_ssl_cipher
These are used to specify the respective parameters of a call
to mysql_ssl_set, if mysql_ssl is turned on.
mysql_local_infile
As of MySQL 3.23.49, the LOCAL capability for LOAD DATA may be
disabled in the MySQL client library by default. If your DSN
contains the option "mysql_local_infile=1", LOAD DATA LOCAL
will be enabled. (However, this option is *ineffective* if the
server has also been configured to disallow LOCAL.)
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 running
on $hostname, port $port. This method is rarely needed for data-
bases running on "localhost": You should use the portable method
@dbs = DBI->data_sources("mysql");
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 "List-
DBs". :-(
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 obtain-
ing this connection you have two options: Either use a driver han-
dle (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 cre-
ate $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):
$errno = $dbh->{'mysql_errno'};
$error = $dbh->{'mysql_error};
$info = $dbh->{'mysql_hostinfo'};
$info = $dbh->{'mysql_info'};
$insertid = $dbh->{'mysql_insertid'};
$info = $dbh->{'mysql_protoinfo'};
$info = $dbh->{'mysql_serverinfo'};
$info = $dbh->{'mysql_stat'};
$threadId = $dbh->{'mysql_thread_id'};
These correspond to mysql_errno(), mysql_error(),
mysql_get_host_info(), mysql_info(), mysql_insert_id(),
mysql_get_proto_info(), mysql_get_server_info(), mysql_stat() and
mysql_thread_id(), respectively.
$info_hashref = $dhb->{mysql_dbd_stats}
DBD::mysql keeps track of some statistics in the mysql_dbd_stats
attribute. The following stats are being maintained:
auto_reconnects_ok
the number of times that DBD::mysql had to reconnect to mysql
failed_auto_reconnects_failed
the number of times that DBD::mysql tried to reconnect to mysql but
failed.
The DBD::mysql driver also supports the following attribute(s) of data-
base handles (read/write):
$bool_value = $dbh->{mysql_auto_reconnect};
$dbh->{mysql_auto_reconnect} = $AutoReconnect ? 1 : 0;
mysql_auto_reconnect
This attribute determines whether DBD::mysql will automatically
reconnect to mysql if the connection be lost. This feature defaults
to off; however, if either the GATEWAY_INTERFACE or MOD_PERL
envionment variable is set, DBD::mysql will turn mysql_auto_recon-
nect on. Setting mysql_auto_reconnect to on is not advised if
'lock tables' is used because if DBD::mysql reconnect to mysql all
table locks will be lost. This attribute is ignored when AutoCom-
mit is turned off, and when AutoCommit is turned off, DBD::mysql
will not automatically reconnect to the server.
STATEMENT HANDLES
The statement handles of DBD::mysql 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 excep-
tion 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 correspond-
ing to the indices of the arrays returned by fetchrow and similar meth-
ods. 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", $i ? "," : "", $$names[$i]);
}
print "\n";
while (my $ref = $sth->fetchrow_arrayref) {
for (my $i = 0; $i < $numFields; $i++) {
printf("%s%s", $i ? "," : "", $$ref[$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::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. 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.
mysql_is_auto_increment
Reference to an array of boolean values; TRUE indicates that the
respective column is an AUTO_INCREMENT column. This is only valid
for MySQL.
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::mysql::FIELD_TYPE_INTER-
VAL is mapped to DBI::SQL_VARCHAR(). If you need the native column
types, use mysql_type. 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 DBD::mysql 2.0416, transactions are supported. The
transaction support works as follows:
o By default AutoCommit mode is on, following the DBI specifications.
o 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.
o The methods
$dbh-E<gt>rollback();
$dbh-E<gt>commit();
will issue the commands COMMIT and ROLLBACK, respectively. A ROLL-
BACK 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:
o You should never change the server variable autocommit manually,
unless you are ignoring DBI's transaction support.
o 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!
}
o 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.
o DBD::mysql has a "reconnect" feature that handles the so-called
MySQL "morning bug": If the server has disconnected, most probably
due to a timeout, then by default the driver will reconnect and
attempt to execute the same SQL statement again. However, this be-
haviour is disabled when AutoCommit is off: Otherwise the transac-
tion state would be completely unpredictable after a reconnect.
o The "reconnect" feature of DBD::mysql can be toggled by using the
mysql_auto_reconnect attribute. This behaviour should be turned off
in code that uses LOCK TABLE because if the database server time
out and DBD::mysql reconnect, table locks will be lost without any
indication of such loss.
SQL EXTENSIONS
Certain metadata functions of 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 mysql_list_fields (C API) for details.
COMPATIBILITY ALERT
The statement attribute TYPE has changed its meaning, as of DBD::mysql
2.0119. 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.
DBD::mysql is a moving target, due to a number of reasons:
- Of course we have to conform the DBI guidelines and developments.
- We have to keep track with the latest MySQL developments.
- And, surprisingly, we 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 it has a little bit life of its
own.
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 "Obsolete Features" 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 "Deprecated Fea-
tures" 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 fea-
tures. See "Historic Features" below.
Example: The statement handle attribute
$sth->{'LENGTH'}
was declared obsolete in DBD::mysql 2.00xy. It was considered depre-
cated in DBD::mysql 2.02xy and removed in 2.04xy.
Obsolete Features
Database handle attributes
The following database handle attributes are declared obsolete in
DBD::mysql 2.09. They will be deprecated in 2.11 and removed in
2.13.
"$dbh->{'errno'}"
Replaced by "$dbh->{'mysql_errno'}"
"$dbh->{'errmsg'}"
Replaced by "$dbh->{'mysql_error'}"
"$dbh->{'hostinfo'}"
Replaced by "$dbh->{'mysql_hostinfo'}"
"$dbh->{'info'}"
Replaced by "$dbh->{'mysql_info'}"
"$dbh->{'protoinfo'}"
Replaced by "$dbh->{'mysql_protoinfo'}"
"$dbh->{'serverinfo'}"
Replaced by "$dbh->{'mysql_serverinfo'}"
"$dbh->{'stats'}"
Replaced by "$dbh->{'mysql_stat'}"
"$dbh->{'thread_id'}"
Replaced by "$dbh->{'mysql_thread_id'}"
Deprecated Features
_ListTables
Replace with the standard DBI method "$dbh->tables()". See also
"$dbh->table_info()". Portable applications will prefer
@tables = map { $_ =~ s/.*\.//; $_ } $dbh-E<gt>tables()
because, depending on the engine, the string "user.table" will be
returned, user being the table owner. The method will be removed in
DBD::mysql version 2.11xy.
Historic Features
_CreateDB
_DropDB
The methods
$dbh-E<gt>func($db, '_CreateDB');
$dbh-E<gt>func($db, '_DropDB');
have been used for creating or dropping databases. They have been
removed in 1.21_07 in favour of
$drh-E<gt>func("createdb", $dbname, $host, "admin")
$drh-E<gt>func("dropdb", $dbname, $host, "admin")
_ListFields
The method
$sth = $dbh-E<gt>func($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-E<gt>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-E<gt>{'mysql_is_num'};
$sth-E<gt>{'mysql_is_key'};
and so on. Thus the method has been removed in 1.21_07.
_NumRows
The method
$sth-E<gt>func('_NumRows');
used to be equivalent to
$sth-E<gt>rows();
and has been removed in 1.21_07.
_InsertID
The method
$dbh-E<gt>func('_InsertID');
used to be equivalent with
$dbh-E<gt>{'mysql_insertid'};
Statement handle attributes
affected_rows
Replaced with $sth->{'mysql_affected_rows'} or the result of
$sth->execute().
format_default_size
Replaced with $sth->{'PRECISION'}.
format_max_size
Replaced with $sth->{'mysql_max_length'}.
format_type_name
Replaced with $sth->{'TYPE'} (portable) or
$sth->{'mysql_type_name'} (MySQL specific).
format_right_justify
Replaced with $sth->->{'TYPE'} (portable) or
$sth->{'mysql_is_num'} (MySQL specific).
insertid
Replaced with $sth->{'mysql_insertid'}.
IS_BLOB
Replaced with $sth->{'TYPE'} (portable) or
$sth->{'mysql_is_blob'} (MySQL specific).
is_blob
Replaced with $sth->{'TYPE'} (portable) or
$sth->{'mysql_is_blob'} (MySQL specific).
IS_PRI_KEY
Replaced with $sth->{'mysql_is_pri_key'}.
is_pri_key
Replaced with $sth->{'mysql_is_pri_key'}.
IS_NOT_NULL
Replaced with $sth->{'NULLABLE'} (do not forget to invert the
boolean values).
is_not_null
Replaced with $sth->{'NULLABLE'} (do not forget to invert the
boolean values).
IS_NUM
Replaced with $sth->{'TYPE'} (portable) or
$sth->{'mysql_is_num'} (MySQL specific).
is_num
Replaced with $sth->{'TYPE'} (portable) or
$sth->{'mysql_is_num'} (MySQL specific).
IS_KEY
Replaced with $sth->{'mysql_is_key'}.
is_key
Replaced with $sth->{'mysql_is_key'}.
MAXLENGTH
Replaced with $sth->{'mysql_max_length'}.
maxlength
Replaced with $sth->{'mysql_max_length'}.
LENGTH
Replaced with $sth->{'PRECISION'} (portable) or
$sth->{'mysql_length'} (MySQL specific)
length
Replaced with $sth->{'PRECISION'} (portable) or
$sth->{'mysql_length'} (MySQL specific)
NUMFIELDS
Replaced with $sth->{'NUM_OF_FIELDS'}.
numfields
Replaced with $sth->{'NUM_OF_FIELDS'}.
NUMROWS
Replaced with the result of $sth->execute() or
$sth->{'mysql_affected_rows'}.
TABLE
Replaced with $sth->{'mysql_table'}.
table
Replaced with $sth->{'mysql_table'}.
MULTITHREADING
The multithreading capabilities of DBD::mysql 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::mysql is believed to be
completely thread safe, if the C libraries are thread safe and you
don't share handles among threads.
The obvious question is: Are the C libraries thread safe? 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 "WIN32 INSTALLA-
TION" below. Others, go on reading.
First of all, you do not need an installed MySQL server for installing
DBD::mysql. However, you need at least the client libraries and possi-
bly the header files, if you are compiling DBD::mysql 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 bina-
ries, then it may be possible to use just selected RPM's like MySQL-
client and MySQL-devel or something similar, depending on the distribu-
tion.
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::mysql
If this fails (which may be the case for a number of reasons, for exam-
ple 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-1.15.tar.gz
Data/Data-ShowTable-3.3.tar.gz
DBD/DBD-mysql-2.1001.tar.gz
Then enter the following commands:
gzip -cd DBI-1.15.tar.gz | tar xf -
cd DBI-1.15
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 DBD-mysql-2.1001.tar.gz | tar xf -
cd DBD-mysql-2.1001
perl Makefile.PL
make
make test
make install
During "perl Makefile.PL" you will be prompted some questions. 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/libmysql-
client.a or /usr/lib/libmysqlclient.so.
WIN32 INSTALLATION
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
If you need an HTTP proxy, you might need to set the environment vari-
able http_proxy, for example like this:
set http_proxy=http://myproxy.com:8080/
As of this writing, DBD::mysql is missing in the ActivePerl 5.8.0
repository. However, Randy Kobes has kindly donated an own distribution
and the following might succeed:
ppm install http://theoryx5.uwinnipeg.ca/ppms/DBD-mysql.ppd
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 distribu-
tion 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:
- The current Perl versions (5.6, as of this writing) do have a prob-
lem with detecting the C libraries. I recommend to apply the fol-
lowing patch:
*** 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
DBD::mysql.
- Extract the DBD::mysql 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
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 Cyg-
Win32 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.
AUTHORS
The current version of DBD::mysql is almost completely written by
Jochen Wiedmann, and is now being maintained by Rudy Lippan (rlip-
pan@remotelinux.com). The first version's author was Alligator
Descartes (descarte@symbolstone.org), who has been aided and abetted by
Gary Shea, Andreas Knig and Tim Bunce amongst others.
The Mysql module was originally written by Andreas Knig <koenig@kultur-
box.de>. The current version, mainly an emulation layer, is from Jochen
Wiedmann.
COPYRIGHT
This module is Copyright (c) 2003 Rudolf Lippan; Large Portions Copy-
right (c) 1997-2003 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
This module is maintained and supported on a mailing list,
perl@lists.mysql.com
To subscribe to this list, send a mail to
perl-subscribe@lists.mysql.com
or
perl-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
http://www.fugue.com/dbi
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 ar-
chives 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!
perl v5.8.6 2004-07-13 DBD::mysql(3)
Man(1) output converted with
man2html