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DBD::File (3)
>> DBD::File (3) ( Разные man: Библиотечные вызовы )
NAME
DBD::File - Base class for writing DBI drivers
SYNOPSIS
This module is a base class for writing other DBDs.
It is not intended to function as a DBD itself.
If you want to access flatfiles, use DBD::AnyData, or DBD::CSV,
(both of which are subclasses of DBD::File).
DESCRIPTION
The DBD::File module is not a true DBI driver, but an abstract
base class for deriving concrete DBI drivers from it. The implication is,
that these drivers work with plain files, for example CSV files or
INI files. The module is based on the SQL::Statement module, a simple
SQL engine.
See DBI for details on DBI, SQL::Statement for details on
SQL::Statement and DBD::CSV or DBD::IniFile for example
drivers.
Metadata
The following attributes are handled by DBI itself and not by DBD::File,
thus they all work like expected:
The following DBI attributes are handled by DBD::File:
AutoCommit
Always on
ChopBlanks
Works
NUM_OF_FIELDS
Valid after "$sth-"execute>
NUM_OF_PARAMS
Valid after "$sth-"prepare>
NAME
Valid after "$sth-"execute>; undef for Non-Select statements.
NULLABLE
Not really working, always returns an array ref of one's, as DBD::CSV
doesn't verify input data. Valid after "$sth-"execute>; undef for
Non-Select statements.
Additional to the DBI attributes, you can use the following dbh
attribute:
f_dir
This attribute is used for setting the directory where CSV files are
opened. Usually you set it in the dbh, it defaults to the current
directory (``.''). However, it is overwritable in the statement handles.
Driver private methods
data_sources
The "data_sources" method returns a list of subdirectories of the current
directory in the form ``DBI:CSV:f_dir=$dirname''.
If you want to read the subdirectories of another directory, use
Note that the list includes all files contained in the directory, even
those that have non-valid table names, from the view of SQL.
KNOWN BUGS
*
The module is using flock() internally. However, this function is not
available on all platforms. Using flock() is disabled on MacOS and
Windows 95: There's no locking at all (perhaps not so important on
MacOS and Windows 95, as there's a single user anyways).
AUTHOR AND COPYRIGHT
This module is currently maintained by
Jeff Zucker < jzucker @ cpan.org >
The original author is Jochen Wiedmann.
Copyright (C) 2004 by Jeff Zucker
Copyright (C) 1998 by Jochen Wiedmann
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.