1DBD::File(3)          User Contributed Perl Documentation         DBD::File(3)
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NAME

6       DBD::File - Base class for writing DBI drivers
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SYNOPSIS

9        This module is a base class for writing other DBDs.
10        It is not intended to function as a DBD itself.
11        If you want to access flatfiles, use DBD::AnyData, or DBD::CSV,
12        (both of which are subclasses of DBD::File).
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DESCRIPTION

15       The DBD::File module is not a true DBI driver, but an abstract base
16       class for deriving concrete DBI drivers from it. The implication is,
17       that these drivers work with plain files, for example CSV files or INI
18       files. The module is based on the SQL::Statement module, a simple SQL
19       engine.
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21       See DBI for details on DBI, SQL::Statement for details on SQL::State‐
22       ment and DBD::CSV or DBD::IniFile for example drivers.
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24       Metadata
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26       The following attributes are handled by DBI itself and not by
27       DBD::File, thus they all work like expected:
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29           Active
30           ActiveKids
31           CachedKids
32           CompatMode             (Not used)
33           InactiveDestroy
34           Kids
35           PrintError
36           RaiseError
37           Warn                   (Not used)
38
39       The following DBI attributes are handled by DBD::File:
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41       AutoCommit
42           Always on
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44       ChopBlanks
45           Works
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47       NUM_OF_FIELDS
48           Valid after "$sth-"execute>
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50       NUM_OF_PARAMS
51           Valid after "$sth-"prepare>
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53       NAME
54           Valid after "$sth-"execute>; undef for Non-Select statements.
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56       NULLABLE
57           Not really working, always returns an array ref of one's, as
58           DBD::CSV doesn't verify input data. Valid after "$sth-"execute>;
59           undef for Non-Select statements.
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61       These attributes and methods are not supported:
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63           bind_param_inout
64           CursorName
65           LongReadLen
66           LongTruncOk
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68       Additional to the DBI attributes, you can use the following dbh
69       attribute:
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71       f_dir
72           This attribute is used for setting the directory where CSV files
73           are opened. Usually you set it in the dbh, it defaults to the cur‐
74           rent directory ("."). However, it is overwritable in the statement
75           handles.
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77       Driver private methods
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79       data_sources
80           The "data_sources" method returns a list of subdirectories of the
81           current directory in the form "DBI:CSV:f_dir=$dirname".
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83           If you want to read the subdirectories of another directory, use
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85               my($drh) = DBI->install_driver("CSV");
86               my(@list) = $drh->data_sources('f_dir' => '/usr/local/csv_data' );
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88       list_tables
89           This method returns a list of file names inside $dbh->{'f_dir'}.
90           Example:
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92               my($dbh) = DBI->connect("DBI:CSV:f_dir=/usr/local/csv_data");
93               my(@list) = $dbh->func('list_tables');
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95           Note that the list includes all files contained in the directory,
96           even those that have non-valid table names, from the view of SQL.
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KNOWN BUGS

99       ·       The module is using flock() internally. However, this function
100               is not available on all platforms. Using flock() is disabled on
101               MacOS and Windows 95: There's no locking at all (perhaps not so
102               important on MacOS and Windows 95, as there's a single user
103               anyways).
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106       This module is currently maintained by
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108       Jeff Zucker < jzucker @ cpan.org >
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110       The original author is Jochen Wiedmann.
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112       Copyright (C) 2004 by Jeff Zucker Copyright (C) 1998 by Jochen Wiedmann
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114       All rights reserved.
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116       You may freely distribute and/or modify this module under the terms of
117       either the GNU General Public License (GPL) or the Artistic License, as
118       specified in the Perl README file.
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SEE ALSO

121       DBI, Text::CSV_XS, SQL::Statement
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125perl v5.8.8                       2006-02-07                      DBD::File(3)
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