Jochen Wiedmann > Msql-Mysql-modules > DBD::mSQL

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NAME ^

DBD::mSQL / DBD::mysql - mSQL and mysql drivers for the Perl5 Database Interface (DBI)

SYNOPSIS ^

    use DBI;

    $driver = "mSQL"; # or "mSQL1";
    $dsn = "DBI:$driver:database=$database;host=$hostname";

    $dbh = DBI->connect($dsn, undef, undef);

        or

    $driver = "mysql";
    $dsn = "DBI:$driver:database=$database;host=$hostname;port=$port";

    $dbh = DBI->connect($dsn, $user, $password);


    $drh = DBI->install_driver("mysql");
    @databases = $drh->func($host, $port, '_ListDBs');
    @tables = $dbh->func( '_ListTables' );

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

    $rc = $drh->func('createdb', $database, $host, $user, $password, 'admin');
    $rc = $drh->func('dropdb', $database, $host, $user, $password, 'admin');
    $rc = $drh->func('shutdown', $host, $user, $password, 'admin');
    $rc = $drh->func('reload', $host, $user, $password, 'admin');

    $rc = $dbh->func('createdb', $database, 'admin');
    $rc = $dbh->func('dropdb', $database, 'admin');
    $rc = $dbh->func('shutdown', 'admin');
    $rc = $dbh->func('reload', 'admin');

EXAMPLE ^

  #!/usr/bin/perl

  use strict;
  use DBI();

  # Connect to the database.
  my $dbh = DBI->connect("DBI:mysql:database=test;host=localhost",
                         "joe", "joe's password",
                         {'RaiseError' => 1});

  # Drop table 'foo'. This may fail, if 'foo' doesn't exist.
  # Thus we put an eval around it.
  eval { $dbh->do("DROP TABLE foo") };
  print "Dropping foo failed: $@\n" if $@;

  # Create a new table 'foo'. This must not fail, thus we don't
  # catch errors.
  $dbh->do("CREATE TABLE foo (id INTEGER, name VARCHAR(20))");

  # INSERT some data into 'foo'. We are using $dbh->quote() for
  # quoting the name.
  $dbh->do("INSERT INTO foo VALUES (1, " . $dbh->quote("Tim") . ")");

  # Same thing, but using placeholders
  $dbh->do("INSERT INTO foo VALUES (?, ?)", undef, 2, "Jochen");

  # Now retrieve data from the table.
  my $sth = $dbh->prepare("SELECT * FROM foo");
  $sth->execute();
  while (my $ref = $sth->fetchrow_hashref()) {
    print "Found a row: id = $ref->{'id'}, name = $ref->{'name'}\n";
  }
  $sth->finish();

  # Disconnect from the database.
  $dbh->disconnect();

DESCRIPTION ^

DBD::mysql and DBD::mSQL are the Perl5 Database Interface drivers for the mysql, mSQL 1.x and mSQL 2.x databases. The drivers are part of the Msql-Mysql-modules package.

In other words: DBD::mSQL and DBD::mysql are an interface between the Perl programming language and the mSQL or mysql programming API that come with the mSQL any mysql relational database management systems. Most functions provided by the respective programming API's are supported. Some rarely used functions are missing, mainly because noone ever requested them. :-)

In what follows we first discuss the use of DBD::mysql and DBD::mSQL, because this is what you will need the most. For installation, see the sections on INSTALLATION, "WIN32 INSTALLATION", "KNOWN PROBLEMS" 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 mSQL or MySQL database servers and send multiple queries to any of them via a simple object oriented interface. Two types of objects are available: database handles and statement handles. Perl returns a database handle to the connect method like so:

  $dbh = DBI->connect("DBI:mSQL:database=$db;host=$host",
                      undef, undef, {RaiseError => 1});

or

  $dbh = DBI->connect("DBI:mysql:database=$db;host=$host",
                      $user, $password, {RaiseError => 1});

Once you have connected to a database, you can can execute SQL statements with:

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

See 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");
  $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;

    $driver = "mSQL";  #  or "mSQL1"
    $dsn = "DBI:$driver:$database";
    $dsn = "DBI:$driver:database=$database;host=$hostname";

    $dbh = DBI->connect($dsn, undef, undef);

        or

    $dsn = "DBI:mysql:$database";
    $dsn = "DBI:mysql:database=$database;host=$hostname";
    $dsn = "DBI:mysql:database=$database;host=$hostname;port=$port";

    $dbh = DBI->connect($dsn, $user, $password);

A database must always be specified.

host
port

The hostname, if not specified or specified as '', will default to an mysql or mSQL daemon running on the local machine on the default port for the UNIX socket.

Should the mysql or mSQL daemon be running on a non-standard port number, you may explicitly state the port number to connect to in the hostname argument, by concatenating the hostname and port number together separated by a colon ( : ) character or by using the port argument. This doesn't work for mSQL 2: You have to create an alternative config file and load it using the msql_configfile attribute, see below.

mysql_client_found_rows

Enables (TRUE value) or disables (FALSE value) the flag CLIENT_FOUND_ROWS while connecting to the MySQL server. This has a somewhat funny effect: Without mysql_client_found_rows, if you perform a query like

  UPDATE $table SET id = 1 WHERE id = 1

then the MySQL engine will always return 0, because no rows have changed. With mysql_client_found_rows however, it will return the number of rows that have an id 1, as some people are expecting. (At least for compatibility to other engines.)

By default this flag is disabled. However, you can enable it by default, when installing the Msql-Mysql-modules with

  perl Makefile.PL --config --mysql-use-client-found-rows
  make
  make install
mysql_compression

As of MySQL 3.22.3, a new feature is supported: If your DSN contains the option "mysql_compression=1", then the communication between client and server will be compressed.

mysql_connect_timeout

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

mysql_read_default_file
mysql_read_default_group

These options can be used to read a config file like /etc/my.cnf or ~/.my.cnf. By default MySQL's C client library doesn't use any config files unlike the client programs (mysql, mysqladmin, ...) that do, but outside of the C client library. Thus you need to explicitly request reading a config file, as in

    $dsn = "DBI:mysql:test;mysql_read_default_file=/home/joe/my.cnf";
    $dbh = DBI->connect($dsn, $user, $password)

The option mysql_read_default_group can be used to specify the default group in the config file: Usually this is the client group, but see the following example:

    [perl]
    host=perlhost

    [client]
    host=localhost

If you read this config file, then you'll be typically connected to localhost. However, by using

    $dsn = "DBI:mysql:test;mysql_read_default_group=perl;"
        . "mysql_read_default_file=/home/joe/my.cnf";
    $dbh = DBI->connect($dsn, $user, $password);

you'll be connected to perlhost. Note that if you specify a default group and do not specify a file, then the default config files will all be read. See the (missing :-) documentation of the C function mysql_options() for details.

mysql_socket

As of MySQL 3.21.15, it is possible to choose the Unix socket that is used for connecting to the server. This is done, for example, with

    mysql_socket=/dev/mysql

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

Private MetaData Methods

ListDBs
    my $drh = DBI->install_driver("mysql");
    @dbs = $drh->func("$hostname:$port", '_ListDBs');
    @dbs = $drh->func($hostname, $port, '_ListDBs');
    @dbs = $dbh->func('_ListDBs');

Returns a list of all databases managed by the mysql daemon or mSQL daemon running on $hostname, port $port. This method is rarely needed for databases running on localhost: You should use the portable method

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

        or

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

whenever possible. It is a design problem of this method, that there's no way of supplying a host name or port number to data_sources, that's the only reason why we still support ListDBs. :-(

ListTables

*WARNING*: This method is obsolete due to DBI's $dbh->table_info().

    @tables = $dbh->func('_ListTables');

Once connected to the desired database on the desired mysql or mSQL mSQL daemon with the DBI-connect()> method, we may extract a list of the tables that have been created within that database.

ListTables returns an array containing the names of all the tables present within the selected database. If no tables have been created, an empty list is returned.

    @tables = $dbh->func( '_ListTables' );
    foreach $table ( @tables ) {
        print "Table: $table\n";
      }

Server Administration

admin
    $rc = $drh->func("createdb", $dbname, [host, user, password,], 'admin');
    $rc = $drh->func("dropdb", $dbname, [host, user, password,], 'admin');
    $rc = $drh->func("shutdown", [host, user, password,], 'admin');
    $rc = $drh->func("reload", [host, user, password,], 'admin');

      or

    $rc = $dbh->func("createdb", $dbname, 'admin');
    $rc = $dbh->func("dropdb", $dbname, 'admin');
    $rc = $dbh->func("shutdown", 'admin');
    $rc = $dbh->func("reload", 'admin');

For server administration you need a server connection. For obtaining this connection you have two options: Either use a driver handle (drh) and supply the appropriate arguments (host, defaults localhost, user, defaults to '' and password, defaults to ''). A driver handle can be obtained with

    $drh = DBI->install_driver('mysql');

Otherwise reuse the existing connection of a database handle (dbh).

There's only one function available for administrative purposes, comparable to the m(y)sqladmin programs. The command being execute depends on the first argument:

createdb

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

dropdb

Drops the database $dbname. Equivalent to "m(y)sqladmin drop $dbname".

It should be noted that database deletion is not prompted for in any way. Nor is it undo-able from DBI.

    Once you issue the dropDB() method, the database will be gone!

These method should be used at your own risk.

shutdown

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

reload

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

DATABASE HANDLES ^

The DBD::mysql driver supports the following attributes of database handles (read only):

    $infoString = $dbh->{'info'};
    $threadId = $dbh->{'thread_id'};
    $insertId = $dbh->{'mysql_insertid'}

These correspond to mysql_info(), mysql_thread_id() and mysql_insertid(), respectively.

STATEMENT HANDLES ^

The statement handles of DBD::mysql and DBD::mSQL support a number of attributes. You access these by using, for example,

  my $numFields = $sth->{'NUM_OF_FIELDS'};

Note, that most attributes are valid only after a successfull execute. An undef value will returned in that case. The most important exception is the mysql_use_result attribute: This forces the driver to use mysql_use_result rather than mysql_store_result. The former is faster and less memory consuming, but tends to block other processes. (That's why mysql_store_result is the default.)

To set the mysql_use_result attribute, use either of the following:

  my $sth = $dbh->prepare("QUERY", { "mysql_use_result" => 1});

or

  my $sth = $dbh->prepare("QUERY");
  $sth->{"mysql_use_result"} = 1;

Column dependent attributes, for example NAME, the column names, are returned as a reference to an array. The array indices are corresponding to the indices of the arrays returned by fetchrow and similar methods. For example the following code will print a header of table names together with all rows:

  my $sth = $dbh->prepare("SELECT * FROM $table");
  if (!$sth) {
      die "Error:" . $dbh->errstr . "\n";
  }
  if (!$sth->execute) {
      die "Error:" . $sth->errstr . "\n";
  }
  my $names = $sth->{'NAME'};
  my $numFields = $sth->{'NUM_OF_FIELDS'};
  for (my $i = 0;  $i < $numFields;  $i++) {
      printf("%s%s", $$names[$i], $i ? "," : "");
  }
  print "\n";
  while (my $ref = $sth->fetchrow_arrayref) {
      for (my $i = 0;  $i < $numFields;  $i++) {
          printf("%s%s", $$ref[$i], $i ? "," : "");
      }
      print "\n";
  }

For portable applications you should restrict yourself to attributes with capitalized or mixed case names. Lower case attribute names are private to DBD::mSQL and DBD::mysql. The attribute list includes:

ChopBlanks

this attribute determines whether a fetchrow will chop preceding and trailing blanks off the column values. Chopping blanks does not have impact on the max_length attribute.

mysql_insertid

MySQL has the ability to choose unique key values automatically. If this happened, the new ID will be stored in this attribute. This attribute is not valid for DBD::mSQL. An alternative way for accessing this attribute is via $dbh->{'mysql_insertid'}. (Note we are using the $dbh in this case!)

mysql_is_blob

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

mysql_is_key

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

mysql_is_num

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

mysql_is_pri_key

Reference to an array of boolean values; TRUE indicates, that the respective column is a primary key. This is only valid for MySQL and mSQL 1.0.x: mSQL 2.x uses indices.

mysql_length
mysql_max_length

A reference to an array of maximum column sizes. The max_length is the maximum physically present in the result table, length gives the theoretically possible maximum. max_length is valid for MySQL only.

NAME

A reference to an array of column names.

NULLABLE

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

NUM_OF_FIELDS

Number of fields returned by a SELECT or LISTFIELDS statement. You may use this for checking whether a statement returned a result: A zero value indicates a non-SELECT statement like INSERT, DELETE or UPDATE.

mysql_table

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

TYPE

A reference to an array of column types. The engine's native column types are mapped to portable types like DBI::SQL_INTEGER() or DBI::SQL_VARCHAR(), as good as possible. Not all native types have a meaningfull equivalent, for example DBD::mSQL::IDX_TYPE() or DBD::mysql::FIELD_TYPE_INTERVAL are mapped to DBI::SQL_VARCHAR(). If you need the native column types, use mysql_type or msql_type, respectively. See below.

mysql_type

A reference to an array of MySQL's native column types, for example DBD::mysql::FIELD_TYPE_SHORT() or DBD::mysql::FIELD_TYPE_STRING(). Use the TYPE attribute, if you want portable types like DBI::SQL_SMALLINT() or DBI::SQL_VARCHAR().

mysql_type_name

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

TRANSACTION SUPPORT ^

Beginning with Msql-Mysql-modules 1.2216, transactions are supported by DBD::mysql. The transaction support works as follows:

Given the above, you should note the following:

SQL EXTENSIONS ^

Certain metadata functions of mSQL and mysql that are available on the C API level, haven't been implemented here. Instead they are implemented as "SQL extensions" because they return in fact nothing else but the equivalent of a statement handle. These are:

LISTFIELDS $table

Returns a statement handle that describes the columns of $table. Ses the docs of msqlListFields or mysql_list_fields (C API) for details.

LISTINDEX $table $index

mSQL only; returns a statement handle that describes the index $index of table $table. See the docs of msqlListIndex for details.

COMPATIBILITY ALERT ^

The statement attribute TYPE has changed its meaning, as of Msql-Mysql-modules 1.19_19. Formerly it used to be the an array of native engine's column types, but it is now an array of portable SQL column types. The old attribute is still available as mysql_type or msql_type, respectively.

The Msql-Mysql-modules are a moving target, due to a number of reasons:

-

Of course they have to conform the DBI guidelines and developments.

-

They have to keep track with the latest MySQL developments.

-

And, surprisingly, they have to be as close to ODBC as possible: This is due to the current direction of DBI.

-

And, last not least, as any tool they have a little bit of own life.

This means that a lot of things had to and have to be changed. As I am not interested in maintaining a lot of compatibility kludges, which only increase the drivers code without being really usefull, I did and will remove some features, methods or attributes.

To ensure a smooth upgrade, the following policy will be applied:

Obsolete features

The first step is to declare something obsolete. This means, that no code is changed, but the feature appears in the list of obsolete features. See "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 Features" below.

Removing features

Finally features will be removed silently in the next major stable release. The feature will be shown in the list of historic features. See "Historic Features" below.

Example: The statement handle attribute

    $sth->{'LENGTH'}

was declared obsolete in Msql-Mysql-modules 1.18xy. It is considered deprecated in Msql-Mysql-modules 1.20xy (current as of this writing) and will finally be removed in Msql-Mysql-modules 1.22xy.

Obsolete Features

_ListTables

This method is obsoleted by DBI's new method

    $dbh->tables()

See also $dbh->table_info(). Portable applications will prefer

    @tables = map { $_ =~ s/.*\.//; $_ } $dbh->tables()

because, depending on the engine, the string "user.table" will be returned, user being the table owner. The method will be deprecated in 1.23_xy and 1.24xy and removed in 1.25_xy and 1.26xy.

Deprecated Features

_InsertID

The method

    $dbh->func('_InsertID');

can be replaced with

    $dbh->{'mysql_insertid'};

The method is deprecated as of 1.21_xy, thus it will be removed in 1.23_xy and 1.24xy.

Statement handle attributes:
affected_rows
IS_PRI_KEY
is_pri_key
IS_NOT_NULL
is_not_null
IS_KEY
is_key
IS_BLOB
is_blob
IS_NUM
is_num
LENGTH
length
MAXLENGTH
maxlength
NUMROWS
numrows
NUMFIELDS
numfields
RESULT
result
TABLE
table
format_max_size
format_default_size
format_type_name

All of the above statement handle attributes are not conforming to DBI's naming conventions, thus they have been declared deprecated in 1.20xy. However, I forgot to insert warnings in the driver. These warnings have been inserted in 1.21_07, thus the attributes will be removed in 1.23_xy and 1.24xy.

In most of the above cases the driver name has been added and the resulting name was lowercased. For example, you use

    $sth->{'mysql_is_num'};

now. IS_NOT_NULL can be replaced with NULLABLE (note you need to invert the logical value!), LENGTH, format_max_size and format_default_size will be dropped in favour of PRECISION, affected_rows and NUMROWS are identical with

    $sth->rows();

and NUMFIELDS is the same as NUM_OF_FIELDS. Finally format_right_justify is the same as mysql_type_name.

Historic Features

_CreateDB
_DropDB

The methods

    $dbh->func($db, '_CreateDB');
    $dbh->func($db, '_DropDB');

have been used for creating or dropping databases. They have been removed in 1.21_07 in favour of

    $drh->func("createdb", $dbname, $host, "admin")
    $drh->func("dropdb", $dbname, $host, "admin")
_ListFields

The method

    $sth = $dbh->func($table, '_ListFields');

has been used to list a tables columns names, types and other attributes. This method has been removed in 1.21_07 in favour of

    $sth = $dbh->prepare("LISTFIELDS $table");
_ListSelectedFields

The method

    $sth->func('_ListSelectedFields');

use to return a hash ref of attributes like 'IS_NUM', 'IS_KEY' and so on. These attributes are now accessible via

    $sth->{'mysql_is_num'};
    $sth->{'mysql_is_key'};

and so on. Thus the method has been removed in 1.21_07.

_NumRows

The method

    $sth->func('_NumRows');

used to be equivalent to

    $sth->rows();

and has been removed in 1.21_07.

MULTITHREADING ^

The multithreading capabilities of the Msql-Mysql-modules depend completely on the underlying C libraries: The modules are working with handle data only, no global variables are accessed or (to the best of my knowledge) thread unsafe functions are called. Thus DBD::mSQL and DBD::mysql are completely thread safe, if the C libraries thread safe and you don't share handles among threads.

The obvious questions is: Are the C libraries thread safe? In the case of mSQL the answer is definitely "no". The C library has a concept of one single active connection at a time and that is not what threads like.

In the case of MySQL the answer is "mostly" and, in theory, you should be able to get a "yes", if the C library is compiled for being thread safe (By default it isn't.) by passing the option -with-thread-safe-client to configure. See the section on How to make a threadsafe client in the manual.

INSTALLATION ^

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

First of all, you do not need an installed MySQL server for installing DBD::mSQL and/or DBD::mysql. However, you need at least the client libraries and possibly the header files, if you are compiling DBD::mysql or DBD::mSQL from source. In the case of MySQL you can create a client-only version by using the configure option --without-server. If you are using precompiled binaries, then it may be possible to use just selected RPM's like MySQL-client and MySQL-devel or something similar, depending on the distribution.

First you need to install the DBI module. For using dbimon, a simple DBI shell it is recommended to install Data::ShowTable another Perl module.

I recommend trying automatic installation via the CPAN module. Try

  perl -MCPAN -e shell

If you are using the CPAN module for the first time, it will prompt you a lot of questions. If you finally receive the CPAN prompt, enter

  install Bundle::DBD::mSQL

or

  install Bundle::DBD::mysql

If this fails (which may be the case for a number of reasons, for example because you are behind a firewall or don't have network access), you need to do a manual installation. First of all you need to fetch the archives from any CPAN mirror, for example

  ftp://ftp.funet.fi/pub/languages/perl/CPAN/modules/by-module

The following archives are required (version numbers may have changed, I choose those which are current as of this writing):

  DBI/DBI-1.13.tar.gz
  Data/Data-ShowTable-3.3.tar.gz
  DBD/Msql-Mysql-modules-1.2217.tar.gz

Then enter the following commands:

  gzip -cd DBI-1.13.tar.gz | tar xf -
  cd DBI-1.13
  perl Makefile.PL
  make
  make test
  make install

  cd ..
  gzip -cd Data-ShowTable-3.3.tar.gz | tar xf -
  cd Data-ShowTable-3.3
  perl Makefile.PL
  make
  make install  # Don't try make test, the test suite is broken

  cd ..
  gzip -cd Msql-Mysql-modules-1.2217.tar.gz | tar xf -
  cd Msql-Mysql-modules-1.2217
  perl Makefile.PL
  make
  make test
  make install

During "perl Makefile.PL" you will be prompted some questions. In particular you have to choose the installed drivers (MySQL, mSQL2 and/or mSQL1). The MySQL driver will be called DBD::mysql, a single mSQL driver will be called DBD::mSQL. If you want to support both mSQL1 and mSQL2, they former will be DBD::mSQL1.

Other questions are the directories with header files and libraries. For example, of your file mysql.h is in /usr/include/mysql/mysql.h, then enter the header directory /usr, likewise for /usr/lib/mysql/libmysqlclient.a or /usr/lib/libmysqlclient.so. For mSQL go looking for msql.h (typically in /usr/include/msql.h and libmsql.a (probably in /usr/lib/libmsql.a).

See the "KNOWN PROBLEMS" section below if you encounter any problems within "make" or "make test".

WIN32 INSTALLATION ^

I have never attempted to install DBD::mSQL under Win32, so this is only for MySQL. If anyone succeeds, please let me know what you did.

If you are using ActivePerl, you may use ppm to install DBD-mysql. For Perl 5.6, upgrade to Build 623 or later, then it is sufficient to run

  ppm install DBI
  ppm install DBD::mysql

The same applied to Perl 5.005.

Otherwise you definitely *need* a C compiler. And it *must* be the same compiler that was being used for compiling Perl itself. If you don't have a C compiler, the file README.win32 from the Perl source distribution tells you where to obtain freely distributable C compilers like egcs or gcc. The Perl sources are available on any CPAN mirror in the src directory, for example

    ftp://ftp.funet.fi/pub/languages/perl/CPAN/src/latest.tar.gz

I recommend using the win32clients package for installing DBD::mysql under Win32, available for download on www.tcx.se. The following steps have been required for me:

-

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 the Msql-Mysql-modules.

-

Extract the Msql-Mysql-modules sources into another directory, for example C:\src\siteperl

-

Open a DOS shell and change directory to C:\src\siteperl.

-

The next step is only required if you repeat building the modules: Make sure that you have a clean build tree by running

  nmake realclean

If you don't have VC++, replace nmake with your flavour of make. If error messages are reported in this step, you may safely ignore them.

-

Run

  perl Makefile.PL

which will prompt you for some settings. The really important ones are:

  Which DBMS do you want to use?

enter a 1 here (MySQL only), and

  Where is your mysql installed? Please tell me the directory that
  contains the subdir include.

where you have to enter the win32clients directory, for example C:\mysql or C:\tmp\mysql.

-

Continued in the usual way:

  nmake
  nmake install

See the first section of "KNOWN PROBLEMS" below.

If you want to create a PPM package for the ActiveState Perl version, then modify the above steps as follows: Run

  perl Makefile.PL NAME=DBD-mysql BINARY_LOCATION=DBD-mysql.tar.gz
  nmake ppd
  nmake

Once that is done, use tar and gzip (for example those from the CygWin32 distribution) to create an archive:

  mkdir x86
  tar cf x86/DBD-mysql.tar blib
  gzip x86/DBD-mysql.tar

Put the files x86/DBD-mysql.tar.gz and DBD-mysql.ppd onto some WWW server and install them by typing

  install http://your.server.name/your/directory/DBD-mysql.ppd

in the PPM program.

KNOWN PROBLEMS ^

1.)

If the MySQL binaries are compiled with gcc or egcs (as the precompiled binaries are), but your Perl is using another compiler, it is likely that you receive an error message like the following when running "make test":

  t/00base............install_driver(mysql) failed: Can't load
  '../blib/arch/auto/DBD/mysql/mysql.so' for module DBD::mysql:
  ../blib/arch/auto/DBD/mysql/mysql.so: undefined symbol: _umoddi3
  at /usr/local/perl-5.005/lib/5.005/i586-linux-thread/DynaLoader.pm
  line 168.

This means, that your linker doesn't include libgcc.a. You have the following options:

a)

Either recompile Perl or Mysql, it doesn't matter which. The important thing is that you use the same compiler for both. This is definitely the recommended solution in the long term.

b)

A simple workaround is to include libgcc.a manually. Do a "make clean" and "make" and in the output wait for a line like

  LD_RUN_PATH="/usr/lib/mysql:/lib" egcs -o
  ../blib/arch/auto/DBD/mysql/mysql.so  -shared -L/usr/local/lib
  dbdimp.o mysql.o -L/usr/lib/mysql -L/usr/lib/mysql -lmysqlclient
  -lm

Repeat the same line in the shell by adding

  -L/usr/lib/gcc-lib/i386-redhat-linux/gcc-2.7.2.3 -lgcc

where the directory is the location of libgcc.a. The best choice for locating this file is executing

  gcc --print-libgcc-file

or

  gcc -v
2.)

There are known problems with shared versions of libmysqlclient, at least on some Linux boxes. If you receive an error message similar to

  install_driver(mysql) failed: Can't load
  '/usr/lib/perl5/site_perl/i586-linux/auto/DBD/mysql/mysql.so'
  for module DBD::mysql: File not found at
  /usr/lib/perl5/i586-linux/5.00404/DynaLoader.pm line 166

then this error message can be misleading: It's not mysql.so that fails being loaded, but libmysqlclient.so!

As a workaround, recompile the Msql-Mysql-modules with

  perl Makefile.PL --static --config
  make
  make test
  make install

This option forces linkage against the static libmysqlclient.a.

3.)

By default mSQL2 is installed to allow local access only. This can break the test scripts akmisc.t, msql1.t and msql2.t. You might notice a message like

  t/akmisc............Can't connect to MSQL server on localhost at
  t/akmisc.t line 131
  Cannot connect: Can't connect to MSQL server on localhost
  It looks as if your server (on localhost) is not up and running.
  This test requires a running server.
  Please make sure your server is running and retry.
  dubious
  Test returned status 10 (wstat 2560, 0xa00)

If this is the case, try to change the value of "Remote_Access" in your msql.conf file to "True". If the value was set intentionally, you might restore the old value after the tests ran ok.

4.)

If linking fails under Win32 because of a missing symbol pthread_cond_init, apply the following patch to dbd/dbdimp.c:

  *** dbd/dbdimp.c.orig Wed Sep 23 14:39:33 1998
  --- dbd/dbdimp.c      Fri Oct 02 10:37:16 1998
  ***************
  *** 1708,1712 ****
  --- 1709,1720 ----
      }
      return TRUE;
    }
  + 
  + #if !defined(_UNIX_)  &&  defined(WIN32)
  + int pthread_cond_init()
  + {
  +   return 0;
  + }
  + #endif

    #endif

(I could make this part of the source distribution, but I think this is an ugly hack and hopefully Monty will fix the missing symbol in the next release of MyODBC.)

5.)

mSQL 2.0.4 had a bug, that caused the test t/40bindparam.t to fail. This bug is fixed in later versions, 2.0.6 and higher.

6.)

From time to time compiling DBD::mSQL fails with messages like

  In file included from ../dbd/myMsql.h:55,
                   from ../dbd/dbdimp.h:32,
                   from dbdimp.c:29:
  /usr/local/Hughes/include/common/portability.h:74:
    redefinition of `u_int'
  /usr/include/sys/types.h:52: `u_int' previously declared here
  /usr/local/Hughes/include/common/portability.h:78: redefinition of
    `ssize_t'
  /usr/include/sys/types.h:116: `ssize_t' previously declared here
  *** Error code 1

A workaroud is using

        perl Makefile.PL --config DEFINE="-DHAVE_SSIZE_T  -DHAVE_U_INT"

KNOWN BUGS ^

The port part of the first argument to the connect call is implemented in an unsafe way when using mSQL. In fact it is just setting the environment variable MSQL_TCP_PORT during the connect call. If another connect call uses another port and the handles are used simultaneously, they will interfere. I doubt that this will ever change.

AUTHORS ^

The current versions of DBD::mSQL and DBD::mysql is almost completely written by Jochen Wiedmann (joe@ispsoft.de). The first version's author was Alligator Descartes(descarte@symbolstone.org), who has been aided and abetted by Gary Shea, Andreas König and Tim Bunce amongst others.

The Msql and Mysql modules have originally been written by Andreas König <koenig@kulturbox.de>. The current version, mainly an emulation layer, is from Jochen Wiedmann.

COPYRIGHT ^

This module is Copyright (c) 1997-1999 Jochen Wiedmann, with code portions Copyright (c)1994-1997 their original authors. This module is released under the same license as Perl itself. See the Perl README for details.

MAILING LIST SUPPORT ^

MAILING LIST SUPPORT ^

This module is maintained and supported on a mailing list,

    msql-mysql-modules@lists.mysql.com

To subscribe to this list, send a mail to

    msql-mysql-modules-subscribe@lists.mysql.com

or

    msql-mysql-modules-digest-subscribe@lists.mysql.com

Mailing list archives are available at

    http://www.progressive-comp.com/Lists/?l=msql-mysql-modules

Additionally you might try the dbi-user mailing list for questions about DBI and its modules in general. Subscribe via

    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 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!

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