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DBD::File (3)
  • >> DBD::File (3) ( Разные man: Библиотечные вызовы )
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    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:

        Active
        ActiveKids
        CachedKids
        CompatMode             (Not used)
        InactiveDestroy
        Kids
        PrintError
        RaiseError
        Warn                   (Not used)
    
    

    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.

    These attributes and methods are not supported:

        bind_param_inout
        CursorName
        LongReadLen
        LongTruncOk
    
    

    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

        my($drh) = DBI->install_driver("CSV");
        my(@list) = $drh->data_sources('f_dir' => '/usr/local/csv_data' );
    
    
    list_tables
    This method returns a list of file names inside $dbh->{'f_dir'}. Example:

        my($dbh) = DBI->connect("DBI:CSV:f_dir=/usr/local/csv_data");
        my(@list) = $dbh->func('list_tables');
    
    

    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.  

    SEE ALSO

    DBI, Text::CSV_XS, SQL::Statement


     

    Index

    NAME
    SYNOPSIS
    DESCRIPTION
    Metadata
    Driver private methods
    KNOWN BUGS
    AUTHOR AND COPYRIGHT
    SEE ALSO


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