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Linux 2.6 - man page for dbd::mysql (linux section 3pm)

DBD::mysql(3pm) 	       User Contributed Perl Documentation		  DBD::mysql(3pm)

       DBD::mysql - MySQL driver for the Perl5 Database Interface (DBI)

	   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");
	   @databases = DBI->data_sources("mysql",
	     {"host" => $host, "port" => $port, "user" => $user, password => $pass});

	   $sth = $dbh->prepare("SELECT * FROM foo WHERE bla");
	   $sth = $dbh->prepare("LISTFIELDS $table");
	   $sth = $dbh->prepare("LISTINDEX $table $index");
	   $numRows = $sth->rows;
	   $numFields = $sth->{'NUM_OF_FIELDS'};

	   $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');


	 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");
	 while (my $ref = $sth->fetchrow_hashref()) {
	   print "Found a row: id = $ref->{'id'}, name = $ref->{'name'}\n";

	 # Disconnect from the database.

       DBD::mysql is the Perl5 Database Interface driver for the MySQL database. In other words:
       DBD::mysql is an interface between the Perl programming 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, and "WIN32 INSTALLATION"
       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 handles. 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 statements with:

	 my $query = sprintf("INSERT INTO foo VALUES (%d, %s)",
			     $number, $dbh->quote("name"));

       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 statement handle with:

	 $sth = $dbh->prepare("SELECT * FROM $table");

       This statement handle can be used for multiple things. First of all you can retreive a row
       of data:

	 my $row = $sth->fetchrow_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
	       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.

	       The hostname, if not specified or specified as '' or 'localhost', will default to
	       a MySQL server running on the local machine using the default for the UNIX socket.
	       To connect to a MySQL server on the local machine via TCP, you must specify the
	       loopback IP address ( as the host.

	       Should the MySQL server 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.

	       To connect to a MySQL server on localhost using TCP/IP, you must specify the
	       hostname as (with the optional port).

	       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.)

	       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

	       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

		=item mysql_init_command

		If your DSN contains the option "mysql_init_command_timeout=##", then
		this SQL statement is executed when connecting to the MySQL server.
		It is automatically re-executed if reconnection occurs.

	       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:



	       (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 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
	       documentation of the C function mysql_options() for details.

	       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


	       Usually there's no need for this option, unless you are using another location for
	       the socket than that built into the client.

	       A true value turns on the CLIENT_SSL flag when connecting to the MySQL database:


	       This means that your communication with the server will be encrypted.

	       If you turn mysql_ssl on, you might also wish to use the following flags:

	       These are used to specify the respective parameters of a call to mysql_ssl_set, if
	       mysql_ssl is turned on.

	       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.)

	       As of MySQL 4.1, support for multiple statements separated by a semicolon (;) may
	       be enabled by using this option. Enabling this option may cause problems if
	       server-side prepared statements are also enabled.

	   Prepared statement support (server side prepare)
	       As of 3.0002_1, server side prepare statements were on by default (if your server
	       was >= 4.1.3). As of 3.0009, they were off by default again due to issues with the
	       prepared statement API (all other mysql connectors are set this way until C API
	       issues are resolved). The requirement to use prepared statements still remains
	       that you have a server >= 4.1.3

	       To use server side prepared statements, all you need to do is set the variable
	       mysql_server_prepare in the connect:

	       $dbh = DBI->connect(
				   { RaiseError => 1, AutoCommit => 1 }

	       * Note: delimiter for this param is ';'

	       There are many benefits to using server side prepare statements, mostly if you are
	       performing many inserts because of that fact that a single statement is prepared
	       to accept multiple insert values.

	       To make sure that the 'make test' step tests whether server prepare works, you
	       just need to export the env variable MYSQL_SERVER_PREPARE:

	       export MYSQL_SERVER_PREPARE=1

	       The option <mysql_embedded_options> can be used to pass 'command-line' options to
	       embedded server.


	       use DBI;
	       $dbh = DBI->connect($testdsn,"a","b");

	       This would cause the command line help to the embedded MySQL server library to be

	       The option <mysql_embedded_groups> can be used to specify the groups in the config
	       file(my.cnf) which will be used to get options for embedded server.  If not
	       specified [server] and [embedded] groups will be used.



   Private MetaData Methods
	       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 server running on $hostname, port
	   $port. This is a legacy method.  Instead, you should use the portable method

	       @dbs = DBI->data_sources("mysql");

   Server Administration
	       $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');


	       $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:

	       Creates the database $dbname. Equivalent to "m(y)sqladmin create $dbname".

	       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.

	       Silently shuts down the database engine. (Without prompting!)  Equivalent to
	       "m(y)sqladmin shutdown".

	       Reloads the servers configuration files and/or tables. This can be particularly
	       important if you modify access privileges or create new users.

       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:

	   The number of times that DBD::mysql successfully reconnected to the mysql server.

	   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 database handles

	$bool_value = $dbh->{mysql_auto_reconnect};
	$dbh->{mysql_auto_reconnect} = $AutoReconnect ? 1 : 0;

	   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_reconnect 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 AutoCommit is turned off, and when AutoCommit is turned
	   off, DBD::mysql will not automatically reconnect to the server.

	   This attribute 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.)

	   It is possible to set default value of the "mysql_use_result" attribute for $dbh using
	   several ways:

	    - through DSN

	      $dbh= DBI->connect("DBI:mysql:test;mysql_use_result=1", "root", "");

	    - after creation of database handle

	      $dbh->{'mysql_use_result'}=0; #disable
	      $dbh->{'mysql_use_result'}=1; #enable

	   It is possible to set/unset the "mysql_use_result" attribute after creation of
	   statement handle. See below.

	   This attribute determines whether DBD::mysql should assume strings stored in the
	   database are utf8.  This feature defaults to off.

	   When set, a data retrieved from a textual column type (char, varchar, etc) will have
	   the UTF-8 flag turned on if necessary.  This enables character semantics on that
	   string.  You will also need to ensure that your database / table / column is
	   configured to use UTF8.  See Chapter 10 of the mysql manual for details.

	   Additionally, turning on this flag tells MySQL that incoming data should be treated as
	   UTF-8.  This will only take effect if used as part of the call to connect().  If you
	   turn the flag on after connecting, you will need to issue the command "SET NAMES utf8"
	   to get the same effect.

	   This option is experimental and may change in future versions.

	   This attribute causes the driver (emulated prepare statements) to attempt to guess if
	   a value being bound is a numeric value, and if so, doesn't quote the value.	This was
	   created by Dragonchild and is one way to deal with the performance issue of using
	   quotes in a statement that is inserting or updating a large numeric value. This was
	   previously called "unsafe_bind_type_guessing" because it is experimental. I have
	   successfully run the full test suite with this option turned on, the name can now be
	   simply "mysql_bind_type_guessing".

	   CAVEAT: Even though you can insert an integer value into a character column, if this
	   column is indexed, if you query that column with the integer value not being quoted,
	   it will not use the index:

	   MariaDB [test]> explain select * from test where value0 = '3' \G
	   *************************** 1. row ***************************
		      id: 1
	     select_type: SIMPLE
		   table: test
		    type: ref possible_keys: value0
		     key: value0
		 key_len: 13
		     ref: const
		    rows: 1
		   Extra: Using index condition 1 row in set (0.00 sec)

	   MariaDB [test]> explain select * from test where value0 = 3
	       -> \G *************************** 1. row ***************************
		      id: 1
	     select_type: SIMPLE
		   table: test
		    type: ALL possible_keys: value0
		     key: NULL
		 key_len: NULL
		     ref: NULL
		    rows: 6
		   Extra: Using where 1 row in set (0.00 sec)

	   See bug: https://rt.cpan.org/Ticket/Display.html?id=43822

	   This attribute causes the driver (emulated prepare statements) will cause any
	   placeholders in comments to be bound. This is not correct prepared statement behavior,
	   but some developers have come to depend on this behavior, so I have made it available
	   in 4.015

	   See bug: https://rt.cpan.org/Ticket/Display.html?id=

	   "mysql_bind_type_guessing" can be turned on via

	    - through DSN

	     my $dbh= DBI->connect('DBI:mysql:test', 'username', 'pass',
	     { mysql_bind_type_guessing => 1})

	     - OR after handle creation

	     $dbh->{mysql_bind_type_guessing} = 1;

	   This attribute causes the driver to not issue 'set autocommit' either through explicit
	   or using mysql_autocommit(). This is particularly useful in the case of using MySQL

	   See the bug report:


	   As well as:


	   "mysql_no_autocommit_cmd" can be turned on via

	    - through DSN

	     my $dbh= DBI->connect('DBI:mysql:test', 'username', 'pass',
	     { mysql_no_autocommit_cmd => 1})

	     - OR after handle creation

	     $dbh->{mysql_no_autocommit_cmd} = 1;

       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 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});


	 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", $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

	   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

	   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!)

	   Reference to an array of boolean values; TRUE indicates, that the respective column is
	   a blob. This attribute is valid for MySQL only.

	   Reference to an array of boolean values; TRUE indicates, that the respective column is
	   a key. This is valid for MySQL only.

	   Reference to an array of boolean values; TRUE indicates, that the respective column
	   contains numeric values.

	   Reference to an array of boolean values; TRUE indicates, that the respective column is
	   a primary key.

	   Reference to an array of boolean values; TRUE indicates that the respective column is
	   an AUTO_INCREMENT column.  This is only valid for MySQL.

	   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.

	   List information of the MySQL client library that DBD::mysql was built against:

	   print "$dbh->{mysql_clientinfo}\n";


	   print "$dbh->{mysql_clientversion}\n";


	   print "$dbh->{mysql_serverversion}\n";


	   A reference to an array of column names.

	   A reference to an array of boolean values; TRUE indicates that this column may contain

	   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.

	   A reference to an array of table names, useful in a JOIN result.

	   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_INTERVAL is mapped to DBI::SQL_VARCHAR().  If you need the
	   native column types, use mysql_type. See below.

	   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().

	   Similar to mysql, but type names and not numbers are returned.  Whenever possible, the
	   ANSI SQL name is preferred.

	   The number of warnings generated during execution of the SQL statement.

       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->{'AutoCommit'} = 0;


	       $dbh->{'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


	   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:

       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 behaviour is disabled when AutoCommit is off: Otherwise the transaction 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.

       As of version 3.0002_5, DBD::mysql supports multiple result sets (Thanks to Guy
       Harrison!). This is the first release of this functionality, so there may be issues.
       Please report bugs if you run into them!

       The basic usage of multiple result sets is

	   while (@row= $sth->fetchrow_array())
	     do stuff;
	 } while ($sth->more_results)

       An example would be:

	 $dbh->do("drop procedure if exists someproc") or print $DBI::errstr;

	 $dbh->do("create procedure somproc() deterministic
	  declare a,b,c,d int;
	  set a=1;
	  set b=2;
	  set c=3;
	  set d=4;
	  select a, b, c, d;
	  select d, c, b, a;
	  select b, a, c, d;
	  select c, b, d, a;
	 end") or print $DBI::errstr;

	 $sth=$dbh->prepare('call someproc()') ||
	 die $DBI::err.": ".$DBI::errstr;

	 $sth->execute || die DBI::err.": ".$DBI::errstr; $rowset=0;
	 do {
	   print "\nRowset ".++$i."\n---------------------------------------\n\n";
	   foreach $colno (0..$sth->{NUM_OF_FIELDS}) {
	     print $sth->{NAME}->[$colno]."\t";
	   print "\n";
	   while (@row= $sth->fetchrow_array())  {
	     foreach $field (0..$#row) {
	       print $row[$field]."\t";
	     print "\n";
	 } until (!$sth->more_results)

       For more examples, please see the eg/ directory. This is where helpful DBD::mysql code
       snippits will be added in the future.

   Issues with Multiple result sets
       So far, the main issue is if your result sets are "jagged", meaning, the number of columns
       of your results vary. Varying numbers of columns could result in your script crashing.
       This is something that will be fixed soon.

       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.

       You can make a single asynchronous query per MySQL connection; this allows you to submit a
       long-running query to the server and have an event loop inform you when it's ready.  An
       asynchronous query is started by either setting the 'async' attribute to a truthy value in
       the "do" in DBI method, or in the "prepare" in DBI method.  Statements created with
       'async' set to true in prepare always run their queries asynchronously when "execute" in
       DBI is called.  The driver also offers three additional methods: "mysql_async_result",
       "mysql_async_ready", and "mysql_fd".  "mysql_async_result" returns what do or execute
       would have; that is, the number of rows affected.  "mysql_async_ready" returns true if
       "mysql_async_result" will not block, and zero otherwise.  They both return "undef" if that
       handle is not currently running an asynchronous query.  "mysql_fd" returns the file
       descriptor number for the MySQL connection; you can use this in an event loop.

       Here's an example of how to use the asynchronous query interface:

	 use feature 'say';
	 $dbh->do('SELECT SLEEP(10)', { async => 1 });
	 until($dbh->mysql_async_ready) {
	   say 'not ready yet!';
	   sleep 1;
	 my $rows = $dbh->mysql_async_result;

       Windows users may skip this section and pass over to WIN32 INSTALLATION below. Others, go
       on reading.

   Environment Variables
       For ease of use, you can now set environment variables for DBD::mysql installation. You
       can set any or all of the options, and export them by putting them in your .bashrc or the

	   export DBD_MYSQL_CFLAGS=-I/usr/local/mysql/include/mysql
	   export DBD_MYSQL_LIBS="-L/usr/local/mysql/lib/mysql -lmysqlclient"
	   export DBD_MYSQL_CONFIG=mysql_config
	   export DBD_MYSQL_SSL=
	   export DBD_MYSQL_TESTDB=test
	   export DBD_MYSQL_TESTHOST=localhost
	   export DBD_MYSQL_TESTPASSWORD=s3kr1+
	   export DBD_MYSQL_TESTPORT=3306
	   export DBD_MYSQL_TESTUSER=me

       The most useful may be the host, database, port, socket, user, and password.

       Installation will first look to your mysql_config, and then your environment variables,
       and then it will guess with intelligent defaults.

   Installing with CPAN
       First of all, you do not need an installed MySQL server for installing DBD::mysql.
       However, you need at least the client libraries and possibly 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
       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::mysql

   Manual Installation
       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 modules from CPAN search


       The following modules are required


       Then enter the following commands (note - versions are just examples):

	 gzip -cd DBI-(version).tar.gz | tar xf -
	 cd DBI-(version)
	 perl Makefile.PL
	 make test
	 make install

	 cd ..
	 gzip -cd Data-ShowTable-(version).tar.gz | tar xf -
	 cd Data-ShowTable-3.3
	 perl Makefile.PL
	 make install

	 cd ..
	 gzip -cd DBD-mysql-(version)-tar.gz | tar xf -
	 cd DBD-mysql-(version)
	 perl Makefile.PL
	 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/libmysqlclient.a or /usr/lib/libmysqlclient.so.

       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 variable 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 distribution tells you where to obtain freely
       distributable C compilers like egcs or gcc. The Perl sources are available via CPAN search


       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 problem with detecting
	   the C libraries. I recommend to apply the following 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

       -   Continued in the usual way:

	     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

       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.

       Originally, there was a non-DBI driver, Mysql, which was much like PHP drivers such as
       mysql and mysqli. The Mysql module was originally written by Andreas Koenig
       <koenig@kulturbox.de> who still, to this day, contributes patches to DBD::mysql. An
       emulated version of Mysql was provided to DBD::mysql from Jochen Wiedmann, but eventually
       deprecated as it was another bundle of code to maintain.

       The first incarnation of DBD::mysql was developed by Alligator Descartes, who was also
       aided and abetted by Gary Shea, Andreas Koenig and Tim Bunce.

       The current incarnation of DBD::mysql was written by Jochen Wiedmann, then numerous
       changes and bug-fixes were added by Rudy Lippan. Next, prepared statement support was
       added by Patrick Galbraith and Alexy Stroganov (who also soley added embedded server

       For the past seven years DBD::mysql has been maintained by Patrick Galbraith
       (patg@patg.net) along with the entire community of Perl developers who keep sending
       patches and making Patrick's job easier.

       Anyone who desires to contribute to this project is encouraged to do so.  Currently, the
       sourcecode for this project can be found at Github:


       Either fork this repository and produce a branch with your changeset that the maintainer
       can merge to his tree, or create a diff with git. The maintainer is more than glad to take
       contributions from the community as many features and fixes from DBD::mysql have come from
       the community.

       This module is Large Portions Copyright (c) 2004-2010 Patrick Galbraith Large Portions
       Copyright (c) 2004-2006 Alexey Stroganov Large Portions Copyright (c) 2003-2005 Rudolf
       Lippan Large Portions Copyright (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.

       This module is maintained and supported on a mailing list,


       To subscribe to this list, go to


       Mailing list archives are available at


       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


       Also, the main DBI site is at


       And source:


       Additional information on the DBI project can be found on the World Wide Web at the
       following URL:


       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!

       Please report bugs, including all the information needed such as DBD::mysql version, MySQL
       version, OS type/version, etc to this link:


perl v5.12.3				    2011-05-15				  DBD::mysql(3pm)

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