# -*- perl -*-
#
# DBD::File - A base class for implementing DBI drivers that
# act on plain files
#
# This module is currently maintained by
#
# H.Merijn Brand & Jens Rehsack
#
# The original author is Jochen Wiedmann.
#
# Copyright (C) 2009 by H.Merijn Brand & Jens Rehsack
# Copyright (C) 2004 by Jeff Zucker
# Copyright (C) 1998 by Jochen Wiedmann
#
# All rights reserved.
#
# You may distribute this module under the terms of either the GNU
# General Public License or the Artistic License, as specified in
# the Perl README file.
require 5.005;
use strict;
use DBI ();
require DBI::SQL::Nano;
require File::Spec;
package DBD::File;
use strict;
use vars qw( @ISA $VERSION $drh $valid_attrs );
$VERSION = "0.37";
$drh = undef; # holds driver handle(s) once initialised
sub driver ($;$)
{
my ($class, $attr) = @_;
# Drivers typically use a singleton object for the $drh
# We use a hash here to have one singleton per subclass.
# (Otherwise DBD::CSV and DBD::DBM, for example, would
# share the same driver object which would cause problems.)
# An alternative would be not not cache the $drh here at all
# and require that subclasses do that. Subclasses should do
# their own caching, so caching here just provides extra safety.
$drh->{$class} and return $drh->{$class};
DBI->setup_driver ("DBD::File"); # only needed once but harmless to repeat
$attr ||= {};
{ no strict "refs";
unless ($attr->{Attribution}) {
$class eq "DBD::File" and $attr->{Attribution} = "$class by Jeff Zucker";
$attr->{Attribution} ||= ${$class . "::ATTRIBUTION"} ||
"oops the author of $class forgot to define this";
}
$attr->{Version} ||= ${$class . "::VERSION"};
$attr->{Name} or ($attr->{Name} = $class) =~ s/^DBD\:\://;
}
$drh->{$class} = DBI::_new_drh ($class . "::dr", $attr);
$drh->{$class}->STORE (ShowErrorStatement => 1);
return $drh->{$class};
} # driver
sub CLONE
{
undef $drh;
} # CLONE
sub file2table
{
my ($data, $dir, $file, $file_is_tab, $quoted) = @_;
$file eq "." || $file eq ".." and return;
my ($ext, $req) = ("", 0, 0);
if ($data->{f_ext}) {
($ext, my $opt) = split m/\//, $data->{f_ext};
if ($ext && $opt) {
$opt =~ m/r/i and $req = 1;
}
}
(my $tbl = $file) =~ s/$ext$//i;
$file_is_tab and $file = "$tbl$ext";
# Fully Qualified File Name
my $fqfn;
unless ($quoted) { # table names are case insensitive in SQL
local *DIR;
opendir DIR, $dir;
my @f = grep { lc $_ eq lc $file } readdir DIR;
@f == 1 and $file = $f[0];
}
$fqfn = File::Spec->catfile ($dir, $file);
$file = $fqfn;
if ($ext) {
if ($req) {
# File extension required
$file =~ s/$ext$//i or return;
}
else {
# File extension optional, skip if file with extension exists
grep m/$ext$/i, glob "$fqfn.*" and return;
$file =~ s/$ext$//i;
}
}
$data->{f_map}{$tbl} = $fqfn;
return $tbl;
} # file2table
# ====== DRIVER ================================================================
package DBD::File::dr;
use strict;
$DBD::File::dr::imp_data_size = 0;
sub connect ($$;$$$)
{
my ($drh, $dbname, $user, $auth, $attr)= @_;
# create a 'blank' dbh
my $this = DBI::_new_dbh ($drh, {
Name => $dbname,
USER => $user,
CURRENT_USER => $user,
});
if ($this) {
my ($var, $val);
$this->{f_dir} = File::Spec->curdir ();
$this->{f_ext} = "";
$this->{f_map} = {};
while (length $dbname) {
if ($dbname =~ s/^((?:[^\\;]|\\.)*?);//s) {
$var = $1;
}
else {
$var = $dbname;
$dbname = "";
}
if ($var =~ m/^(.+?)=(.*)/s) {
$var = $1;
($val = $2) =~ s/\\(.)/$1/g;
$this->{$var} = $val;
}
}
$this->{f_valid_attrs} = {
f_version => 1, # DBD::File version
f_dir => 1, # base directory
f_ext => 1, # file extension
f_schema => 1, # schema name
f_tables => 1, # base directory
};
$this->{sql_valid_attrs} = {
sql_handler => 1, # Nano or S:S
sql_nano_version => 1, # Nano version
sql_statement_version => 1, # S:S version
};
}
$this->STORE ("Active", 1);
return set_versions ($this);
} # connect
sub set_versions
{
my $this = shift;
$this->{f_version} = $DBD::File::VERSION;
for (qw( nano_version statement_version)) {
$this->{"sql_$_"} = $DBI::SQL::Nano::versions->{$_} || "";
}
$this->{sql_handler} = $this->{sql_statement_version}
? "SQL::Statement"
: "DBI::SQL::Nano";
return $this;
} # set_versions
sub data_sources ($;$)
{
my ($drh, $attr) = @_;
my $dir = $attr && exists $attr->{f_dir}
? $attr->{f_dir}
: File::Spec->curdir ();
my ($dirh) = Symbol::gensym ();
unless (opendir ($dirh, $dir)) {
$drh->set_err ($DBI::stderr, "Cannot open directory $dir: $!");
return;
}
my ($file, @dsns, %names, $driver);
if ($drh->{ImplementorClass} =~ m/^dbd\:\:([^\:]+)\:\:/i) {
$driver = $1;
}
else {
$driver = "File";
}
while (defined ($file = readdir ($dirh))) {
if ($^O eq "VMS") {
# if on VMS then avoid warnings from catdir if you use a file
# (not a dir) as the file below
$file !~ m/\.dir$/oi and next;
}
my $d = File::Spec->catdir ($dir, $file);
# allow current dir ... it can be a data_source too
$file ne File::Spec->updir () && -d $d and
push @dsns, "DBI:$driver:f_dir=$d";
}
@dsns;
} # data_sources
sub disconnect_all
{
} # disconnect_all
sub DESTROY
{
undef;
} # DESTROY
# ====== DATABASE ==============================================================
package DBD::File::db;
use strict;
use Carp;
$DBD::File::db::imp_data_size = 0;
sub ping
{
return (shift->FETCH ("Active")) ? 1 : 0;
} # ping
sub prepare ($$;@)
{
my ($dbh, $statement, @attribs) = @_;
# create a 'blank' sth
my $sth = DBI::_new_sth ($dbh, {Statement => $statement});
if ($sth) {
my $class = $sth->FETCH ("ImplementorClass");
$class =~ s/::st$/::Statement/;
my $stmt;
# if using SQL::Statement version > 1
# cache the parser object if the DBD supports parser caching
# SQL::Nano and older SQL::Statements don't support this
if ( $dbh->{sql_handler} eq "SQL::Statement" and
$dbh->{sql_statement_version} > 1) {
my $parser = $dbh->{csv_sql_parser_object};
$parser ||= eval { $dbh->func ("csv_cache_sql_parser_object") };
if ($@) {
$stmt = eval { $class->new ($statement) };
}
else {
$stmt = eval { $class->new ($statement, $parser) };
}
}
else {
$stmt = eval { $class->new ($statement) };
}
if ($@) {
$dbh->set_err ($DBI::stderr, $@);
undef $sth;
}
else {
$sth->STORE ("f_stmt", $stmt);
$sth->STORE ("f_params", []);
$sth->STORE ("NUM_OF_PARAMS", scalar ($stmt->params ()));
}
}
$sth;
} # prepare
sub csv_cache_sql_parser_object
{
my $dbh = shift;
my $parser = {
dialect => "CSV",
RaiseError => $dbh->FETCH ("RaiseError"),
PrintError => $dbh->FETCH ("PrintError"),
};
my $sql_flags = $dbh->FETCH ("sql_flags") || {};
%$parser = (%$parser, %$sql_flags);
$parser = SQL::Parser->new ($parser->{dialect}, $parser);
$dbh->{csv_sql_parser_object} = $parser;
return $parser;
} # csv_cache_sql_parser_object
sub disconnect ($)
{
shift->STORE ("Active", 0);
1;
} # disconnect
sub FETCH ($$)
{
my ($dbh, $attrib) = @_;
$attrib eq "AutoCommit" and
return 1;
if ($attrib eq (lc $attrib)) {
# Driver private attributes are lower cased
# Error-check for valid attributes
# not implemented yet, see STORE
#
return $dbh->{$attrib};
}
# else pass up to DBI to handle
return $dbh->SUPER::FETCH ($attrib);
} # FETCH
sub STORE ($$$)
{
my ($dbh, $attrib, $value) = @_;
if ($attrib eq "AutoCommit") {
$value and return 1; # is already set
croak "Can't disable AutoCommit";
}
if ($attrib eq lc $attrib) {
# Driver private attributes are lower cased
# I'm not implementing this yet becuase other drivers may be
# setting f_ and sql_ attrs I don't know about
# I'll investigate and publicize warnings to DBD authors
# then implement this
# return to implementor if not f_ or sql_
# not implemented yet
# my $class = $dbh->FETCH ("ImplementorClass");
#
# !$dbh->{f_valid_attrs}->{$attrib} && !$dbh->{sql_valid_attrs}->{$attrib} and
# return $dbh->set_err ($DBI::stderr, "Invalid attribute '$attrib'");
# $dbh->{$attrib} = $value;
if ($attrib eq "f_dir") {
-d $value or
return $dbh->set_err ($DBI::stderr, "No such directory '$value'")
}
if ($attrib eq "f_ext") {
$value eq "" || $value =~ m{^\.\w+(?:/[rR]*)?$}
or carp "'$value' doesn't look like a valid file extension attribute\n";
}
$dbh->{$attrib} = $value;
return 1;
}
return $dbh->SUPER::STORE ($attrib, $value);
} # STORE
sub DESTROY ($)
{
my $dbh = shift;
$dbh->SUPER::FETCH ("Active") and $dbh->disconnect ;
} # DESTROY
sub type_info_all ($)
{
[ { TYPE_NAME => 0,
DATA_TYPE => 1,
PRECISION => 2,
LITERAL_PREFIX => 3,
LITERAL_SUFFIX => 4,
CREATE_PARAMS => 5,
NULLABLE => 6,
CASE_SENSITIVE => 7,
SEARCHABLE => 8,
UNSIGNED_ATTRIBUTE => 9,
MONEY => 10,
AUTO_INCREMENT => 11,
LOCAL_TYPE_NAME => 12,
MINIMUM_SCALE => 13,
MAXIMUM_SCALE => 14,
},
[ "VARCHAR", DBI::SQL_VARCHAR (),
undef, "'", "'", undef, 0, 1, 1, 0, 0, 0, undef, 1, 999999,
],
[ "CHAR", DBI::SQL_CHAR (),
undef, "'", "'", undef, 0, 1, 1, 0, 0, 0, undef, 1, 999999,
],
[ "INTEGER", DBI::SQL_INTEGER (),
undef, "", "", undef, 0, 0, 1, 0, 0, 0, undef, 0, 0,
],
[ "REAL", DBI::SQL_REAL (),
undef, "", "", undef, 0, 0, 1, 0, 0, 0, undef, 0, 0,
],
[ "BLOB", DBI::SQL_LONGVARBINARY (),
undef, "'", "'", undef, 0, 1, 1, 0, 0, 0, undef, 1, 999999,
],
[ "BLOB", DBI::SQL_LONGVARBINARY (),
undef, "'", "'", undef, 0, 1, 1, 0, 0, 0, undef, 1, 999999,
],
[ "TEXT", DBI::SQL_LONGVARCHAR (),
undef, "'", "'", undef, 0, 1, 1, 0, 0, 0, undef, 1, 999999,
]];
} # type_info_all
{ my $names = [
qw( TABLE_QUALIFIER TABLE_OWNER TABLE_NAME TABLE_TYPE REMARKS )];
sub table_info ($)
{
my $dbh = shift;
my $dir = $dbh->{f_dir};
my $dirh = Symbol::gensym ();
unless (opendir $dirh, $dir) {
$dbh->set_err ($DBI::stderr, "Cannot open directory $dir: $!");
return;
}
my ($file, @tables, %names);
my $schema = exists $dbh->{f_schema}
? $dbh->{f_schema}
: eval { getpwuid ((stat $dir)[4]) };
while (defined ($file = readdir ($dirh))) {
my $tbl = DBD::File::file2table ($dbh, $dir, $file, 0, 0) or next;
push @tables, [ undef, $schema, $tbl, "TABLE", undef ];
}
unless (closedir $dirh) {
$dbh->set_err ($DBI::stderr, "Cannot close directory $dir: $!");
return;
}
my $dbh2 = $dbh->{csv_sponge_driver};
unless ($dbh2) {
$dbh2 = $dbh->{csv_sponge_driver} = DBI->connect ("DBI:Sponge:");
unless ($dbh2) {
$dbh->set_err ($DBI::stderr, $DBI::errstr);
return;
}
}
# Temporary kludge: DBD::Sponge dies if @tables is empty. :-(
@tables or return;
my $sth = $dbh2->prepare ("TABLE_INFO", {
rows => \@tables,
NAMES => $names,
});
$sth or $dbh->set_err ($DBI::stderr, $dbh2->errstr);
$sth;
} # table_info
}
sub list_tables ($)
{
my $dbh = shift;
my ($sth, @tables);
$sth = $dbh->table_info () or return;
while (my $ref = $sth->fetchrow_arrayref ()) {
push @tables, $ref->[2];
}
@tables;
} # list_tables
sub quote ($$;$)
{
my ($self, $str, $type) = @_;
defined $str or return "NULL";
defined $type && (
$type == DBI::SQL_NUMERIC ()
|| $type == DBI::SQL_DECIMAL ()
|| $type == DBI::SQL_INTEGER ()
|| $type == DBI::SQL_SMALLINT ()
|| $type == DBI::SQL_FLOAT ()
|| $type == DBI::SQL_REAL ()
|| $type == DBI::SQL_DOUBLE ()
|| $type == DBI::SQL_TINYINT ())
and return $str;
$str =~ s/\\/\\\\/sg;
$str =~ s/\0/\\0/sg;
$str =~ s/\'/\\\'/sg;
$str =~ s/\n/\\n/sg;
$str =~ s/\r/\\r/sg;
"'$str'";
} # quote
sub commit ($)
{
my $dbh = shift;
$dbh->FETCH ("Warn") and
carp "Commit ineffective while AutoCommit is on", -1;
1;
} # commit
sub rollback ($)
{
my $dbh = shift;
$dbh->FETCH ("Warn") and
carp "Rollback ineffective while AutoCommit is on", -1;
0;
} # rollback
# ====== STATEMENT =============================================================
package DBD::File::st;
use strict;
$DBD::File::st::imp_data_size = 0;
sub bind_param ($$$;$)
{
my ($sth, $pNum, $val, $attr) = @_;
if ($attr && defined $val) {
my $type = ref $attr eq "HASH" ? $attr->{TYPE} : $attr;
if ( $attr == DBI::SQL_BIGINT ()
|| $attr == DBI::SQL_INTEGER ()
|| $attr == DBI::SQL_SMALLINT ()
|| $attr == DBI::SQL_TINYINT ()
) {
$val += 0;
}
elsif ($attr == DBI::SQL_DECIMAL ()
|| $attr == DBI::SQL_DOUBLE ()
|| $attr == DBI::SQL_FLOAT ()
|| $attr == DBI::SQL_NUMERIC ()
|| $attr == DBI::SQL_REAL ()
) {
$val += 0.;
}
else {
$val = "$val";
}
}
$sth->{f_params}[$pNum - 1] = $val;
1;
} # bind_param
sub execute
{
my $sth = shift;
my $params = @_ ? ($sth->{f_params} = [ @_ ]) : $sth->{f_params};
$sth->finish;
my $stmt = $sth->{f_stmt};
unless ($sth->{f_params_checked}++) {
# bug in SQL::Statement 1.20 and below causes breakage
# on all but the first call
unless ((my $req_prm = $stmt->params ()) == (my $nparm = @$params)) {
my $msg = "You passed $nparm parameters where $req_prm required";
$sth->set_err ($DBI::stderr, $msg);
return;
}
}
my @err;
my $result = eval {
local $SIG{__WARN__} = sub { push @err, @_ };
$stmt->execute ($sth, $params);
};
if ($@ || @err) {
$sth->set_err ($DBI::stderr, $@ || $err[0]);
return undef;
}
if ($stmt->{NUM_OF_FIELDS}) { # is a SELECT statement
$sth->STORE (Active => 1);
$sth->FETCH ("NUM_OF_FIELDS") or
$sth->STORE ("NUM_OF_FIELDS", $stmt->{NUM_OF_FIELDS})
}
return $result;
} # execute
sub finish
{
my $sth = shift;
$sth->SUPER::STORE (Active => 0);
delete $sth->{f_stmt}->{data};
return 1;
} # finish
sub fetch ($)
{
my $sth = shift;
my $data = $sth->{f_stmt}->{data};
if (!$data || ref $data ne "ARRAY") {
$sth->set_err ($DBI::stderr,
"Attempt to fetch row without a preceeding execute () call or from a non-SELECT statement"
);
return
}
my $dav = shift @$data;
unless ($dav) {
$sth->finish;
return
}
if ($sth->FETCH ("ChopBlanks")) {
$_ && $_ =~ s/\s+$// for @$dav;
}
$sth->_set_fbav ($dav);
} # fetch
*fetchrow_arrayref = \&fetch;
my %unsupported_attrib = map { $_ => 1 } qw( TYPE PRECISION );
sub FETCH ($$)
{
my ($sth, $attrib) = @_;
exists $unsupported_attrib{$attrib}
and return undef; # Workaround for a bug in DBI 0.93
$attrib eq "NAME" and
return $sth->FETCH ("f_stmt")->{NAME};
if ($attrib eq "NULLABLE") {
my ($meta) = $sth->FETCH ("f_stmt")->{NAME}; # Intentional !
$meta or return undef;
return [ (1) x @$meta ];
}
if ($attrib eq lc $attrib) {
# Private driver attributes are lower cased
return $sth->{$attrib};
}
# else pass up to DBI to handle
return $sth->SUPER::FETCH ($attrib);
} # FETCH
sub STORE ($$$)
{
my ($sth, $attrib, $value) = @_;
exists $unsupported_attrib{$attrib}
and return; # Workaround for a bug in DBI 0.93
if ($attrib eq lc $attrib) {
# Private driver attributes are lower cased
$sth->{$attrib} = $value;
return 1;
}
return $sth->SUPER::STORE ($attrib, $value);
} # STORE
sub DESTROY ($)
{
my $sth = shift;
$sth->SUPER::FETCH ("Active") and $sth->finish;
} # DESTROY
sub rows ($)
{
shift->{f_stmt}->{NUM_OF_ROWS};
} # rows
package DBD::File::Statement;
use strict;
use Carp;
# We may have a working flock () built-in but that doesn't mean that locking
# will work on NFS (flock () may hang hard)
my $locking = eval { flock STDOUT, 0; 1 };
# Jochen's old check for flock ()
#
# my $locking = $^O ne "MacOS" &&
# ($^O ne "MSWin32" || !Win32::IsWin95 ()) &&
# $^O ne "VMS";
@DBD::File::Statement::ISA = qw( DBI::SQL::Nano::Statement );
my $open_table_re = sprintf "(?:%s|%s|%s)",
quotemeta (File::Spec->curdir ()),
quotemeta (File::Spec->updir ()),
quotemeta (File::Spec->rootdir ());
sub get_file_name ($$$)
{
my ($self, $data, $table) = @_;
my $quoted = 0;
$table =~ s/^\"// and $quoted = 1; # handle quoted identifiers
$table =~ s/\"$//;
my $file = $table;
if ( $file !~ m/^$open_table_re/o
and $file !~ m{^[/\\]} # root
and $file !~ m{^[a-z]\:} # drive letter
) {
exists $data->{Database}{f_map}{$table} or
DBD::File::file2table ($data->{Database},
$data->{Database}{f_dir}, $file, 1, $quoted);
$file = $data->{Database}{f_map}{$table} || undef;
}
return ($table, $file);
} # get_file_name
sub open_table ($$$$$)
{
my ($self, $data, $table, $createMode, $lockMode) = @_;
my $file;
($table, $file) = $self->get_file_name ($data, $table);
defined $file && $file ne "" or croak "No filename given";
require IO::File;
my $fh;
my $safe_drop = $self->{ignore_missing_table} ? 1 : 0;
if ($createMode) {
-f $file and
croak "Cannot create table $table: Already exists";
$fh = IO::File->new ($file, "a+") or
croak "Cannot open $file for writing: $!";
$fh->seek (0, 0) or
croak "Error while seeking back: $!";
}
else {
unless ($fh = IO::File->new ($file, ($lockMode ? "r+" : "r"))) {
$safe_drop or croak "Cannot open $file: $!";
}
}
$fh and binmode $fh;
if ($locking and $fh) {
if ($lockMode) {
flock $fh, 2 or croak "Cannot obtain exclusive lock on $file: $!";
}
else {
flock $fh, 1 or croak "Cannot obtain shared lock on $file: $!";
}
}
my $columns = {};
my $array = [];
my $pos = $fh ? $fh->tell () : undef;
my $tbl = {
file => $file,
fh => $fh,
col_nums => $columns,
col_names => $array,
first_row_pos => $pos,
};
my $class = ref $self;
$class =~ s/::Statement/::Table/;
bless $tbl, $class;
$tbl;
} # open_table
package DBD::File::Table;
use strict;
use Carp;
@DBD::File::Table::ISA = qw(DBI::SQL::Nano::Table);
sub drop ($)
{
my $self = shift;
# We have to close the file before unlinking it: Some OS'es will
# refuse the unlink otherwise.
$self->{fh} and $self->{fh}->close ();
unlink $self->{file};
return 1;
} # drop
sub seek ($$$$)
{
my ($self, $data, $pos, $whence) = @_;
if ($whence == 0 && $pos == 0) {
$pos = $self->{first_row_pos};
}
elsif ($whence != 2 || $pos != 0) {
croak "Illegal seek position: pos = $pos, whence = $whence";
}
$self->{fh}->seek ($pos, $whence) or
croak "Error while seeking in " . $self->{file} . ": $!";
} # seek
sub truncate ($$)
{
my ($self, $data) = @_;
$self->{fh}->truncate ($self->{fh}->tell ()) or
croak "Error while truncating " . $self->{file} . ": $!";
1;
} # truncate
1;
__END__
=head1 NAME
DBD::File - Base class for writing DBI drivers
=head1 SYNOPSIS
This module is a base class for writing other DBDs.
It is not intended to function as a DBD itself.
If you want to access flatfiles, use DBD::AnyData, or DBD::CSV,
(both of which are subclasses of DBD::File).
=head1 DESCRIPTION
The DBD::File module is not a true DBI driver, but an abstract
base class for deriving concrete DBI drivers from it. The implication is,
that these drivers work with plain files, for example CSV files or
INI files. The module is based on the SQL::Statement module, a simple
SQL engine.
See L for details on DBI, L for details on
SQL::Statement and L or L for example
drivers.
=head2 Metadata
The following attributes are handled by DBI itself and not by DBD::File,
thus they all work like expected:
Active
ActiveKids
CachedKids
CompatMode (Not used)
InactiveDestroy
Kids
PrintError
RaiseError
Warn (Not used)
The following DBI attributes are handled by DBD::File:
=over 4
=item AutoCommit
Always on
=item ChopBlanks
Works
=item NUM_OF_FIELDS
Valid after C<$sth->execute>
=item NUM_OF_PARAMS
Valid after C<$sth->prepare>
=item NAME
Valid after C<$sth->execute>; undef for Non-Select statements.
=item NULLABLE
Not really working, always returns an array ref of one's, as DBD::CSV
doesn't verify input data. Valid after C<$sth->execute>; undef for
Non-Select statements.
=back
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:
=over 4
=item 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.
=item f_ext
This attribute is used for setting the file extension where (CSV) files are
opened. There are several possibilities.
DBI:CSV:f_dir=data;f_ext=.csv
In this case, DBD::File will open only C if both C and
C exist in the datadir. The table will still be named C. If
your datadir has files with extensions, and you do not pass this attribute,
your table is named C, which is probably not what you wanted. The
extension is always case-insensitive. The table names are not.
DBI:CSV:f_dir=data;f_ext=.csv/r
In this case the extension is required, and all filenames that do not match
are ignored.
=item f_schema
This will set the schema name. Default is the owner of the folder in which
the table file resides. C is allowed.
my $dbh = DBI->connect ("dbi:CSV:", "", "", {
f_schema => undef,
f_dir => "data",
f_ext => ".csv/r",
}) or die $DBI::errstr;
The effect is that when you get table names from DBI, you can force all
tables into the same (or no) schema:
my @tables $dbh->tables ();
# no f_schema
"merijn".foo
"merijn".bar
# f_schema => "dbi"
"dbi".foo
"dbi".bar
# f_schema => undef
foo
bar
=back
=head2 Driver private methods
=over 4
=item data_sources
The C method returns a list of subdirectories of the current
directory in the form "DBI:CSV:f_dir=$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" );
=item 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.
=back
=head1 KNOWN BUGS
=over 8
=item *
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).
=back
=head1 AUTHOR
This module is currently maintained by
H.Merijn Brand < h.m.brand at xs4all.nl > and
Jens Rehsack < rehsack at googlemail.com >
The original author is Jochen Wiedmann.
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2009 by H.Merijn Brand & Jens Rehsack
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.
=head1 SEE ALSO
L, L, L, L
=cut