DBD::Mem

NAME

DBD::Mem − a DBI driver for Mem & MLMem files

SYNOPSIS

use DBI;
$dbh = DBI−>connect('dbi:Mem:', undef, undef, {});
$dbh = DBI−>connect('dbi:Mem:', undef, undef, {RaiseError => 1});
# or
$dbh = DBI−>connect('dbi:Mem:');
$dbh = DBI−>connect('DBI:Mem(RaiseError=1):');

and other variations on connect() as shown in the DBI docs and <DBI::DBD::SqlEngine metadata|DBI::DBD::SqlEngine/Metadata>.

Use standard DBI prepare, execute, fetch, placeholders, etc., see " QUICK START" for an example.

DESCRIPTION

DBD::Mem is a database management system that works right out of the box. If you have a standard installation of Perl and DBI you can begin creating, accessing, and modifying simple database tables without any further modules. You can add other modules (e.g., SQL::Statement) for improved functionality.

DBD::Mem doesn’t store any data persistently − all data has the lifetime of the instantiated $dbh. The main reason to use DBD::Mem is to use extended features of SQL::Statement where temporary tables are required. One can use DBD::Mem to simulate "VIEWS" or sub-queries.

Bundling "DBD::Mem" with DBI will allow us further compatibility checks of DBI::DBD::SqlEngine beyond the capabilities of DBD::File and DBD::DBM . This will ensure DBI provided basis for drivers like DBD::AnyData2 or DBD::Amazon are better prepared and tested for not-file based backends.

Metadata
There’re no new meta data introduced by "DBD::Mem". See "Metadata" in DBI::DBD::SqlEngine for full description.

GETTING HELP, MAKING SUGGESTIONS, AND REPORTING BUGS

If you need help installing or using DBD::Mem, please write to the DBI users mailing list at <mailto:dbi−users@perl.org> or to the comp.lang.perl.modules newsgroup on usenet. I cannot always answer every question quickly but there are many on the mailing list or in the newsgroup who can.

DBD developers for DBD ’s which rely on DBI::DBD::SqlEngine or DBD::Mem or use one of them as an example are suggested to join the DBI developers mailing list at <mailto:dbi−dev@perl.org> and strongly encouraged to join our IRC channel at <irc://irc.perl.org/dbi>.

If you have suggestions, ideas for improvements, or bugs to report, please report a bug as described in DBI. Do not mail any of the authors directly, you might not get an answer.

When reporting bugs, please send the output of "$dbh−>mem_versions($table)" for a table that exhibits the bug and as small a sample as you can make of the code that produces the bug. And of course, patches are welcome, too :−).

If you need enhancements quickly, you can get commercial support as described at <http://dbi.perl.org/support/> or you can contact Jens Rehsack at rehsack@cpan.org for commercial support.

AUTHOR AND COPYRIGHT

This module is written by Jens Rehsack < rehsack AT cpan.org >.

Copyright (c) 2016− by Jens Rehsack, all rights reserved.

You may freely distribute and/or modify this module under the terms of either the GNU General Public License ( GPL ) or the Artistic License, as specified in the Perl README file.

SEE ALSO

DBI for the Database interface of the Perl Programming Language.

SQL::Statement and DBI::SQL::Nano for the available SQL engines.

SQL::Statement::RAM where the implementation is shamelessly stolen from to allow DBI bundled Pure-Perl drivers increase the test coverage.

DBD::SQLite using "dbname=:memory:" for an incredible fast in-memory database engine.