How do I use Perl to push into an array of arrays?

Question

Below is a snippet of Perl code. I would like to loop through several queries with different regular expression ($myo) and for different operators ($op) and save the results to an array of arrays rather than one large @result array.

I.e., the array of results for MYO[0-9]*$ would be an array for each operator $results[0][0], $results[0][1] ... and for MYO[0-9]*R$, $results[1][0], $results[1][1].

Any ideas?

my @tech_ops =  ("AR","DB","GM","LW","MM","SA");
  my @results;

    for my $myo (qw(MYO[0-9]*$ MYO[0-9]*R$ MYO[0-9]*T$ MYO[0-9]*U$)) {
      foreach $op (@tech_ops)
        {
           $sth->execute($myo, $date_stop, $date_start,$op) 
         or die "Couldn't execute query for $myo: " . $sth->errstr;
           push @results, $sth->fetchrow_array;
         }
    }

I'm guessing that your SQL is only returning one column; if not, do you really want an array of arrays of arrays? — ysth
– ysth, Commented Jan 18, 2013 at 17:38
The array of array idea was to make it easier to populate the results into a latex table using a for loop. Probably not the most efficient solution but the first one i came up with — moadeep
– moadeep, Commented Jan 18, 2013 at 17:51

Jeffrey Ray · Accepted Answer · 2013-01-18 17:24:13Z

6

Use the fetchall_arrayref method instead of the fetchrow_array method.

So just replace this line:

push @results, $sth->fetchrow_array;

With this line:

push @results, $sth->fetchall_arrayref;

Here is the documentation for all the DBI statement handler methods.

edited Jan 18, 2013 at 17:24

answered Jan 18, 2013 at 17:10

Jeffrey Ray

1,2642 gold badges9 silver badges20 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

ysth · Accepted Answer · 2013-01-18 17:21:53Z

4

my @tech_ops =  ("AR","DB","GM","LW","MM","SA");
my @results;

for my $myo (qw(MYO[0-9]*$ MYO[0-9]*R$ MYO[0-9]*T$ MYO[0-9]*U$)) {
    my @myo_results;
    foreach $op (@tech_ops) {
        $sth->execute($myo, $date_stop, $date_start,$op) 
            or die "Couldn't execute query for $myo: " . $sth->errstr;
        push @myo_results, $sth->fetchrow_array;
    }
    push @results, \@myo_results;
}

answered Jan 18, 2013 at 17:21

ysth

99.1k6 gold badges126 silver badges219 bronze badges

Comments

user1972382 · Accepted Answer · 2013-01-18 17:17:47Z

0

You could just use an array reference:

my $ref;
for my $i (1..10) {
   for my $j (1..10) {
        push @{$ref->[$i]}, $j;
    }
}

That will do it.

EDIT: This will create a reference to a 10x10 matrix.

answered Jan 18, 2013 at 17:17

user1972382

Collectives™ on Stack Overflow

How do I use Perl to push into an array of arrays?

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related