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.
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.
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.