Re: How do I sort a CSV file on multiple columns?

Following up on the DBD::CSV suggestions by others this may get you started:

use strict;
use warnings;
use DBI;

my $tmpFileName = 'temp';
open my $outFile, '>', $tmpFileName or die "Can't open $tmpFileName: $
+!\n";
print $outFile $_ for <DATA>;
close $outFile;

my $dbh = DBI->connect ("DBI:CSV:")
    or die "DBI connect failed: $DBI::errstr";
my $sth = $dbh->prepare ("SELECT * FROM temp ORDER BY Name, Score");

$sth->execute();
while (my $row = $sth->fetchrow_hashref) {
    print "@{$row}{'Name', 'Score', 'State'}\n";
}
$sth->finish();
$dbh->disconnect();


__DATA__
Name,Score,State
"001","67","CA"
"2","67","CA"
"12","63","FL"
"1","72","IL"
"1","32","AZ"
[download]

Prints:

1 32 AZ
001 67 CA
1 72 IL
2 67 CA
12 63 FL
[download]

True laziness is hard work

Comment on Re: How do I sort a CSV file on multiple columns? Select or Download Code

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Re^2: How do I sort a CSV file on multiple columns?
by Tux (Canon) on Dec 10, 2009 at 16:33 UTC

I'd like to note (and obviously promote) the use of new syntax in DBD::CSV available now:

my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
    PrintError    => 1,
    RaiseError    => 1,

    f_dir         => ".",
    f_ext         => ".csv/r",
    f_schema      => undef,

    csv_null      => 1,
    csv_auto_diag => 1,
    });
[download]

Using f_ext like that enables you to mix code (.pl-files) and data (.csv-files) in a single directory, and still be able to only see the tables (without the .csv extension).

merijn@tux:~> cat xx.pl
#!/pro/bin/perl

use strict;
use warnings;

use DBI;

my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
    RaiseError  => 1,
    PrintError  => 1,

    f_dir       => ".",
    f_ext       => ".csv/r",
    f_schema    => undef,

    csv_null    => 1,
    csv_auto_diag       => 1,
    });
my $sth = $dbh->prepare ("select b, e from xx order by d, f");
   $sth->execute;
while (my @row = $sth->fetchrow_array) {
    print "@row\n";
    }
merijn@tux:~> cat xx.csv
a,b,c,d,e,f
1,2,3,4,5,6
1,3,4,5,3,4
2,5,2,5,2,5
2,4,1,5,8,1
3,5,2,8,1,9
4,5,6,7,8,9
5,1,4,2,5,3
6,2,5,7,1,8
merijn@tux:~> ls -d x*
x0  x1  xloadall  xx  xx.csv  xx.pl
merijn@tux:~> perl xx.pl
2 5
3 3
5 2
4 8
5 1
5 8
1 5
2 1
merijn@tux:~>
[download]

Enjoy, Have FUN! H.Merijn

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