Joining and Applying a different hash to another

drewboy has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I have two hashes, both of which result from a MYSQL query. The first hash, for example, looks like this:

$cat = ('username' => 'Drew', 'password' => 'Boy');
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The hash above came from a bigger set of hashes that came from a mysql query that was split. This is assuming that the query had many results.

There is another mysql query that results to a hash (let's call it $results) containing several smaller sets of hashes. A sample 'smaller hash' from this query would look like:

$link = ('Name' => 'Andy', 'PW' => 'Girl');
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My question is, how can I insert the first sample hash ($cat) to $results and at the same time change the names of the keys to 'Name' and 'PW' in place of 'username' and 'password'? Any help will be very much appreciated.

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Re: Joining and Applying a different hash to another by dragonchild (Archbishop) on May 14, 2004 at 20:35 UTC
Well, it sounds like you have two hashes, each containing the same type of keys, but they don't have the same key names. So, it sounds like you need a third hash, mapping old_key to new_key. `my %keymap = ( username => 'Name', password => 'PW', ); my $old = { username => 'Drew', password => 'Boy' }; my $new = {}; foreach my $k (keys %$old) { $new->{$keymap{$k}} = $old->{$k}; }` [download] ------ We are the carpenters and bricklayers of the Information Age. Then there are Damian modules.... sigh* ... that's not about being less-lazy -- that's about being on some really good drugs -- you know, there is no spoon.* - flyingmoose I shouldn't have to say this, but any code, unless otherwise stated, is untested	[reply] [d/l]
Re: Joining and Applying a different hash to another by Zaxo (Archbishop) on May 14, 2004 at 20:36 UTC
Something like, `@{$results}{qw/Name PW/} = @{$cat}{qw/username password/};` Those are hash slices on the dereferenced hashes. After Compline, Zaxo	[reply] [d/l]
Re: Joining and Applying a different hash to another by duff (Parson) on May 14, 2004 at 20:39 UTC
Unless I'm missing something ... `my %trans = ('username' => 'Name', 'password' => 'PW'); for my $k (keys %hash1) { $hash2{$trans{$k}} = $hash1{$k} }` [download] duff	[reply] [d/l]