Trouble converting array to hash

Question

I have an array where elements of the array have values that are separated by tabs. For example:

client_name \t owner \t date \t port_number.

I need to convert that into a hash so it can be dumped into a MySQL database. Something like:

my %foo = ();
$foo{date} = "111208";
$foo{port} = "2222";
$foo{owner} = "ownername";
$foo{name} = "clientname";

The problem I have is that there are duplicate client names but they exist on different port numbers. If I convert it directly to a hash using client_name as a key it will delete duplicate client names. The MySQL table is indexed based on {name} and {port}.

Is there any way I can convert this into a hash without losing duplicate client names?

CanSpice · Accepted Answer · 2011-12-08 19:26:57Z

4

You would go through your file, build up the hash like you've done, then push a reference to that hash onto an array. Something like:

foreach my $line ( @lines ) {
  # Make your %foo hash.
  push @clients, \%foo;
}

Then afterwards, when you're inserting into your DB, you just iterate through the elements in @clients:

foreach my $client ( @clients ) {
  $date = $client->{'date'};
  ...
}

Edit: If you want to turn this into a hash of hashes, then as you loop through the list of lines, you'd do something like:

foreach my $line ( @lines ) {
  # Make your %foo hash.
  $clients{$foo{'port'}} = \%foo;
}

Then you'll have a hash of hashes using the port number as the key.

edited Dec 8, 2011 at 19:26

answered Dec 8, 2011 at 17:52

CanSpice

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2 Comments

cottageDog Over a year ago

I have a module that uses a hash to insert into the database, so I wanted to keep it as a hash. One thought I had would be to create a hash of hashes that uses the port number as the key.

Borodin Over a year ago

@cottageDog: There are endless ways of putting your data into a hash, but everything depends on what form your module requires the hash to be in. Is this module a public one with documenation we can read? Or can you give us an example of a database insertion using it?

BRPocock · Accepted Answer · 2011-12-08 17:54:49Z

1

Why not just store it in a list (array)?

my @records = ();
while (my $line = <INFILE>) {
  chomp $line;
  my @fields = split /\t/ $line;
  push @records => { date => $fields[2],
                     name => $fields[0],
                     port => $fields[3],
                     owner => $fields[1] };
}
for my $record (@records) {
   $insert_query->execute (%$record);
}

answered Dec 8, 2011 at 17:54

BRPocock

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Comments

Axeman · Accepted Answer · 2011-12-08 20:25:17Z

0

my @record_list;
while ( <$generic_input> ) { 
     my $foo = {};
     @$foo{ qw<date port owner name> } = split /\t/;
     push @record_list, \%foo;
 }

As a "pipeline" you could do this:

use List::MoreUtils qw<pairwise>;
my @fields = qw<date port owner name>;
my @records 
    = map {; { pairwise { $a => $b } @fields, @{[ split /\t/ ]}}}
      <$input>
    ;

edited Dec 8, 2011 at 20:25

answered Dec 8, 2011 at 20:17

Axeman

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