Re: Example in Cookbook of hash of hash

How do we get many records from such a contruction?

By repeating the assignment with different $record.

my %byname;
for my $record (
   {
      NAME => "Jason",
      EMPNO => "132",
   },
   {
      NAME => "Orange",
      EMPNO => "133",
   },
) {
   $byname{ $record->{NAME} } = $record;
}

print(Dumper(\%byname));
[download]

In reality, your record source would be a database or LDAP or something rather than a hardcoded list.

Update:

Oh wait, are you asking how to access the records?

To access one record:

my $record = $byname{$name};
[download]

To access each record:

for my $name ( keys(%byname) ) {
    my $record = $byname{$name};
    ...
}
[download]

To access each record, sorted by id:

for my $name (
    sort { $byname{$a}{EMPNO} <=> $byname{$b}{EMPNO} }
        keys(%byname)
) {
    my $record = $byname{$name};
    ...
}
[download]

To check if an employee exists,

if (exists($byname{$name})) {
    # yes
} else {
    # no
}
[download]

Comment on Re: Example in Cookbook of hash of hash Select or Download Code

Replies are listed 'Best First'.
Re^2: Example in Cookbook of hash of hash by theantler (Beadle) on Mar 26, 2010 at 18:58 UTC
Ikegami, thanks for your useful reply! What is going on in that for declaration? I have never seen it before like that and am confused about the position of the byname declaration, it almost looks like it part of the hash.	[reply]
Re^3: Example in Cookbook of hash of hash by ikegami (Patriarch) on Mar 26, 2010 at 19:17 UTC
Are you asking about `my %byname;`?	[reply] [d/l]
Re^4: Example in Cookbook of hash of hash by theantler (Beadle) on Mar 26, 2010 at 19:26 UTC
Ikegami, I am confused about `{ $byname{ $record->{NAME} } = $record; }` [download] Is it part of a for loop?	[reply] [d/l]
Re^5: Example in Cookbook of hash of hash by ikegami (Patriarch) on Mar 26, 2010 at 20:37 UTC
Re^2: Example in Cookbook of hash of hash by theantler (Beadle) on Mar 27, 2010 at 07:56 UTC
When we make the value of $byname the reference to $record, I thought that we would get the same reference over and over again. I dont see where the reference changes, but I can see from the dump that it does in fact and work just fine.	[reply]
Re^3: Example in Cookbook of hash of hash by theantler (Beadle) on Mar 27, 2010 at 09:26 UTC
Guys, THANK you, especialy Ikegami for taking the time to help me. I finally figured out the for-loop by writing in this way making it more clear to me: `my %byname; use Data::Dumper; for my $record ( { NAME => "Jason", EMPNO => "132" }, { NAME => "Orang +e", EMPNO => "133" } ) { $byname{ $record->{NAME} } = $record; }; print $byname{Orange}->{EMPNO};` [download]	[reply] [d/l]