You want to split up array @all_st into subgroups of 30 each, I think. You can easily do this using the module List::MoreUtils' function natatime.

You are just a beginner, so you probably aren't aware that, instead of creating 3 or however many separate subarrays of @all_st, you can create an array of arrays like. . . $store_get2[0][0]. This notation would access the first item in the first 'subarray'.

You should read perllol which will explain this better than me :-)

(You would probably be better off not appending a comma to your data at this stage of your program. It could more easily done later with a join ",", @some_list).

Here is an example of using natatime

#!/usr/bin/perl
use strict;
use warnings;
use List::MoreUtils qw/ natatime /;
use Data::Dumper;

my @all_st = 1..125;
my @store_get;

my $it = natatime 30, @all_st;

while (my @vals = $it->()) {
    push @store_get, [@vals];
}

print Dumper \@store_get;

__END__
C:\perlp>perl t3.pl
$VAR1 = [
          [
            1,
            2,
            3,
            4,
            5,
            6,
            7,
            8,
            9,
            10,
            11,
            12,
            13,
            14,
            15,
            16,
            17,
            18,
            19,
            20,
            21,
            22,
            23,
            24,
            25,
            26,
            27,
            28,
            29,
            30
          ],
          [
            31,
            32,
            33,
            34,
            35,
            36,
            37,
            38,
            39,
            40,
            41,
            42,
            43,
            44,
            45,
            46,
            47,
            48,
            49,
            50,
            51,
            52,
            53,
            54,
            55,
            56,
            57,
            58,
            59,
            60
          ],
          [
            61,
            62,
            63,
            64,
            65,
            66,
            67,
            68,
            69,
            70,
            71,
            72,
            73,
            74,
            75,
            76,
            77,
            78,
            79,
            80,
            81,
            82,
            83,
            84,
            85,
            86,
            87,
            88,
            89,
            90
          ],
          [
            91,
            92,
            93,
            94,
            95,
            96,
            97,
            98,
            99,
            100,
            101,
            102,
            103,
            104,
            105,
            106,
            107,
            108,
            109,
            110,
            111,
            112,
            113,
            114,
            115,
            116,
            117,
            118,
            119,
            120
          ],
          [
            121,
            122,
            123,
            124,
            125
          ]
        ];

C:\perlp>
[download]

Update A better solution that uses no module and doesn't keep 2 sets of data when only one set is probably required. Also, it puts the data into a form that can be used for an *in* clause for a SQL select statement (single quotes enclosing the items for the *in* clause).

#!/usr/bin/perl
use strict;
use warnings;

my @all_st = 1..125;
my @store_get;

while (@all_st) {
    push @store_get, join ",", map "'$_'", splice @all_st, 0, 30;
}
[download]

Update: The in keyword will accept unquoted data if the type is integer. So the line above doesn't need the quotes added

push @store_get, join ",", splice @all_st, 0, 30;
[download]