Trying to access array of arrays

kris1511 has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks!! This is format of data that I am receiving from SQL object - @result. I need to access @result[0]

 for $aref ( @result ) {
                         print "\t [ @$aref ],\n";
                     }

Gives output like

ARRAY(0x4b72d28) ARRAY(0x4ba58d8) ARRAY(0x4bdb108)

Print Dumper @results; Output looks like one below

$VAR1 = [ [ '8959', 'The song by the three rivers', undef, undef ],
          [ '10710', 'cars by the rodeo drive', '38', undef],
          [ '10710', 'cars by the rodeo drive', '43', undef]

          ];
[download]

I need to access elements 8959, 10710, 10710 to find their distinct count. For now am not sure how to access them. Any kinds of pointers will be helpful

Comment on Trying to access array of arrays Download Code

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Re: Trying to access array of arrays by ikegami (Patriarch) on Aug 21, 2017 at 21:24 UTC
You should pass scalars to `Dumper`, so `print Dumper @results;` [download] should be `print Dumper \@results;` [download] This gives `[ [ [ '8959', 'The song by the three rivers', undef, undef ], [ '10710', 'cars by the rodeo drive', '38', undef], [ '10710', 'cars by the rodeo drive', '43', undef] ] ]` [download] As you can see, the outer array (`@results`) contains a single element, your AoA. You should therefore use `my $records = $result[0]; for my $record ( @$records ) { print "\t [ @$record ]\n"; }` [download]	[reply] [d/l] [select]
Re: Trying to access array of arrays by shmem (Chancellor) on Aug 21, 2017 at 22:20 UTC
I need to access elements 8959, 10710, 10710 to find their distinct count. To help you, it would be helpful if you posted the code which populates the array `@result`. This array holds array references, whose first element is the thing you are looking looking for to get the distinct count, right? Well, use them as key to a hash and sum them up: `my %distinct; for my $aref ( @result ) { $distinct{$aref->[0]}++; } print Dumper(\%distinct);` [download] perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'	[reply] [d/l] [select]
Re: Trying to access array of arrays by AnomalousMonk (Archbishop) on Aug 22, 2017 at 03:15 UTC
Not really sure what you want. For general information on this, please see the Perl Data Structures Cookbook. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l]
Re: Trying to access array of arrays by thanos1983 (Parson) on Aug 22, 2017 at 08:24 UTC
Hello kris1511, Well it seems the monks have provided you ~~the~~ solution to your problem already. But taking this opportunity I think it would be better to use fetchrow_arrayref or fetchrow_array or selectall_arrayref. From what I am seeing you querying you DB to fetch the all the data where you could simply fetch only one column. There is a similar question with sample of code that replicates the behavior for `fetchrow_array()` and also `selectall_arrayref()` how to save data to new array after retrieving from sql server. Update: Also you can find some code examples here extract column data. Hope this helps, BR. Seeking for Perl wisdom...on the process of learning...not there...yet!	[reply] [d/l] [select]