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DBD::mysql - phpMan

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    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 no-one 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 execute SQL statements

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

    See DBI for details on the quote and do methods. An alternative approach

      $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. 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 retrieve 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 compressed.

            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.

            If your DSN contains the option "mysql_write_timeout=##", the
            write operation to the server will timeout if it has not been
            successful after the given number of seconds.

            If your DSN contains the option "mysql_read_timeout=##", the read
            operation to the server will timeout if it has not been successful
            after the given number of seconds.

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

            This option is for older mysql databases that don't have secure
            auth set

            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,


            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

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

            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

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

            export MYSQL_SERVER_PREPARE=1

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


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

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

            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 mysqladmin programs. The command being execute
        depends on the first argument:

            Creates the database $dbname. Equivalent to "mysqladmin create

            Drops the database $dbname. Equivalent to "mysqladmin drop

            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 "mysqladmin 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

    The DBD::mysql driver also supports the following attribute(s) of database
    handles (read/write):

     $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 environment
        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.

        It is also possible to set the default value of the
        "mysql_auto_reconnect" attribute for the $dbh by passing it in the
        "\%attr" hash for "DBI-"connect>.

        Note that if you are using a module or framework that performs
        reconnections for you (for example DBIx::Connector in fixup mode),
        this value must be set to 0.

        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. mysql_store_result is the default
        due to that fact storing the result is expected behavior with most

        It is possible to set the default value of the "mysql_use_result"
        attribute for the $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 the 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

        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

        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

        "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 (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

        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 Proxy.

        See the bug report:


        "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 successful 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'} - 1;
      for my $i ( 0..$numFields ) {
          printf("%s%s", $i ? "," : "", $$names[$i]);
      print "\n";
      while (my $ref = $sth->fetchrow_arrayref) {
          for my $i ( 0..$numFields ) {
              printf("%s%s", $i ? "," : "", $$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:

        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 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

        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

        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 NULL's.

        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
        meaningful 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

        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. This attribute is available on both statement handles and
        database handles.

    Beginning with DBD::mysql 2.0416, transactions are supported. The
    transaction support works as follows:

    *   By default AutoCommit mode is on, following the DBI specifications.

    *   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.

    *   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

    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.

    *   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.

    *   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 someproc() 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}-1) {
          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 snippets 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 true 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 like:

        export DBD_MYSQL_CFLAGS=-I/usr/local/mysql/include/mysql
        export DBD_MYSQL_LIBS="-L/usr/local/mysql/lib/mysql -lmysqlclient"
        export DBD_MYSQL_EMBEDDED=
        export DBD_MYSQL_CONFIG=mysql_config
        export DBD_MYSQL_NOFOUNDROWS=0
        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

    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.

    I recommend trying automatic installation via the CPAN module. Try


    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 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


    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 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

    The MariaDB native client is another option for connecting to a MySQL
    database licensed LGPL 2.1. To build DBD::mysql against this client, you
    will first need to build the client. Generally, this is done with the

      cd path/to/src/mariadb-native-client
      cmake -G "Unix Makefiles'
      sudo make install

    Once the client is built and installed, you can build DBD::mysql against

      perl Makefile.PL --testuser=xxx --testpassword=xxx --testsocket=/path/to//mysqld.sock --mysql_config=/usr/local/bin/mariadb_config
      make test
      make install

    If you are using ActivePerl, you may use ppm to install DBD-mysql.

      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/

    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:

    -   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

    -   Open a CMD.exe 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 flavor 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

          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 install

    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 König <koenig AT 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 König 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 solely added embedded server support).

    For the past nine years DBD::mysql has been maintained by Patrick
    Galbraith (patg AT patg.net), and recently with the great help of Michiel
    Beijen (michiel.beijen AT gmail.com), along with the entire community of Perl
    developers who keep sending patches to help continue improving DBD::mysql

    Anyone who desires to contribute to this project is encouraged to do so.
    Currently, the source code 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) 2004-2013 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

    *   Copyright (c)1994-1997 their original authors

    This module is released under the same license as Perl itself. See
    <http://www.perl.com/perl/misc/Artistic.html> for details.

    This module is maintained and supported on a mailing list, dbi-users.

    To subscribe to this list, send an email to

    dbi-users-subscribe AT perl.org

    Mailing list archives are at


    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

    Information on the DBI interface itself can be gained by typing:

        perldoc DBI

    Information on DBD::mysql specifically can be gained by typing:

        perldoc DBD::mysql

    (this will display the document you're currently reading)

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


    Note: until recently, MySQL/Sun/Oracle responded to bugs and assisted in
    fixing bugs which many thanks should be given for their help! This driver
    is outside the realm of the numerous components they support, and the
    maintainer and community solely support DBD::mysql

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