Re^3: Generating a Hash of Hashes Recursively to Display Database Hierarchy

I dare say your join is broken and that's what should be fixed. But it's easy to work with it anyway.

You have:

my $data = [
   [ 'parent1', 'child1a', 'child2a', undef,    ],
   [ 'parent1', 'child1b', 'child2b', 'child3b',],
   [ 'parent1', 'child1c', undef, undef,],
];
[download]

You want:

my $data = [
   [ 'parent1', 'child1a' ],
   [ 'parent1', 'child2a' ],
   [ 'parent1', 'child1b' ],
   [ 'parent1', 'child2b' ],
   [ 'parent1', 'child3b' ],
   [ 'parent1', 'child1c' ],
];
[download]

Easy! Change

    while (my $row = $sth->fetch()) {
        my ($id, $parent_id) = @$row;
        ...
    }
[download]

    while (my $row = $sth->fetch()) {
        my ($parent_id, @children_ids) = @$row;
        for my $id (grep defined, @children_ids) {
            ...
        }
    }
[download]

Comment on Re^3: Generating a Hash of Hashes Recursively to Display Database Hierarchy Select or Download Code

Replies are listed 'Best First'.
Re^4: Generating a Hash of Hashes Recursively to Display Database Hierarchy by c4onastick (Friar) on Jun 23, 2009 at 16:59 UTC
Ah, my apologies! My short hand with `$data` got a little too short! `$data` really looks like this: `my $data = [ [ 'parent1', 'child1', 'grand_child1', undef, ], [ 'parent1', 'child2', 'grand_child2', 'great_grand_child1',], [ 'parent1', 'child3', undef, undef,], ];` [download] Or: `my $data = [ [ 'parent1', 'child1' ], [ 'child1', 'grand_child1' ], [ 'parent1', 'child2' ], [ 'child2', 'grand_child2' ], [ 'grand_child2', 'great_grand_child2' ], [ 'parent1', 'child1c' ], ];` [download] But because of our extended table structure, I'm sure how I can (easily) make it look like the second form though.	[reply] [d/l] [select]
Re^5: Generating a Hash of Hashes Recursively to Display Database Hierarchy by ikegami (Patriarch) on Jun 23, 2009 at 17:17 UTC
With the top: `while (my $row = $sth->fetch()) { for (1..$#$row) { my ($parent_id, $id) = @{$row}[$i-1, $i-0]; last if !defined($id); ... } }` [download] With the bottom: `while (my $row = $sth->fetch()) { my ($parent_id, $id) = @$row; ... }` [download]	[reply] [d/l] [select]