Re^2: tree-oriented query against table-oriented data

i guess, this will not exist, because it is actually a combination of querying data from a database and displaying the result.

That is one way of evaluating the problem, however it is possible to 'rethink' the situation if you strip away pre-existing paradigms, methodologies, and ask the following:

Given this:

sitcom/simpsons/homer/simpson
sitcom/simpsons/ned/flanders
sitcom/flintstones/fred/flintstone
sitcom/flintstones/wilma/flintstone
sitcom/flintstones/barney/rubble
gameshow/price is right/bob/barker
gameshow/jeopardy/alex/trebek
[download]

What can I use to transform it into this?:

$dataroot = {
  'gameshow' => {
      'price is right' => [
            {
              'lname' => 'barker',
              'fname' => 'bob'
            }
                          ],
      'jeopardy' => [
          {
            'lname' => 'trebek',
            'fname' => 'alex'
          }
                    ]
    },
  'sitcom' => {
    'simpsons' => [
        {
          'lname' => 'simpson',
          'fname' => 'homer'
        },
        {
          'lname' => 'flanders',
          'fname' => 'ned'
        }
                  ],
    'flintstones' => [
       {
         'lname' => 'flintstone',
         'fname' => 'fred'
       },
       {
         'lname' => 'flintstone',
         'fname' => 'wilma'
       },
       {
         'lname' => 'rubble',
         'fname' => 'barney'
       }
                     ]
    }
};
[download]

The key consideration here is a simple question of transforming the flat 'row-based' representation into a 'nested representation'. This does not necessarily involve a database at all. Nor does it necessarily involve 'displaying' anything (unless you count using Data::Dumper to show the output for illustrative purposes only).

=oQDlNWYsBHI5JXZ2VGIulGIlJXYgQkUPxEIlhGdgY2bgMXZ5VGIlhGV

Comment on Re^2: tree-oriented query against table-oriented data Select or Download Code

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Re^3: tree-oriented query against table-oriented data by BrowserUk (Patriarch) on Jul 04, 2006 at 22:57 UTC
Try this: #! perl -slw use strict; use List::Util qw[ reduce ]; use Data::Dumper; my %data; while( <DATA> ) { my( $genre, $title, $fname, $lname ) = split '/'; $data{ $genre } = {} unless exists $data{ $genre }; $data{ $genre }{ $title } = [] unless exists $data{ $genre }{ $tit +le }; push @{ $data{ $genre }{ $title } }, { fname => $fname, lname => $ +lname }; }; print Dumper \%data; __DATA__ sitcom/simpsons/homer/simpson sitcom/simpsons/ned/flanders sitcom/flintstones/fred/flintstone sitcom/flintstones/wilma/flintstone sitcom/flintstones/barney/rubble gameshow/price is right/bob/barker gameshow/jeopardy/alex/trebek [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]
Re^3: tree-oriented query against table-oriented data by dimar (Curate) on Jul 05, 2006 at 15:11 UTC
Just to refocus on the OP, the question was, (given the example 'one-off' solution that BrowserUk illustrated for this specific example, and considering the similarly-coded 'one-off' solutions by the OP in the past) where does there exist a "general purpose" mechanism to further abstract the process of doing this kind of transformation, such that there is no need to modify the 'one-off' code every time someone wants a different 'pivot' of the data structure. The question is now mostly academic, since the humble aspirant has gone on to code a solution himself, absent a preexisting and obvious choice out there. It is called 'vpath_pivot', named after the 'pivot table' feature found in spreadsheet software. It generates arbitrarily-nested tree structures using perl data variables, constructed from queries like: `### 1: provides same output as BrowserUk example TREE_SELECT genre,title,fname,lname FROM tvshow WITH_LEVELS ('genre','title' ) WITH_RECORD ( 'lname','fname' ) ### 2: a different 'pivot' of the same data TREE_SELECT title,genre,fname,lname FROM tvshow WITH_LEVELS ('title','genre','lname' ) WITH_RECORD ( 'fname' ) WHERE genre != 'gameshow' ### 3: another tree 'pivot' (more compact) TREE_SELECT title,fname,lname FROM tvshow WITH_LEVELS ('title' ) WITH_RECORD ( 'fname','lname' )` [download] NOTE: the above is not SQL, it just looks similar for readability. NOTE: the main approach here is to give the user the ability to 'slice and dice' the 'flat' data into different 'tree structures' all within a simple syntax (i.e., no need to re-edit the perl code). tyvm for the replies =oQDlNWYsBHI5JXZ2VGIulGIlJXYgQkUPxEIlhGdgY2bgMXZ5VGIlhGV	[reply] [d/l]


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