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


 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.


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.


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


If you need help installing or using DBD::Mem, please write to the DBI users mailing list at 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 and strongly encouraged to join our IRC channel at irc://

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 or you can contact Jens Rehsack at for commercial support.


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

 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.


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.