A Laravel migration to add neutral_sort function to MySQL and Postgres DB

neutral sorting.php

<?php

use Illuminate\Database\Migrations\Migration;

use Illuminate\Database\Schema\Blueprint;

use Illuminate\Support\Facades\DB;

use Illuminate\Support\Facades\Schema;

return new class extends Migration

{

    /**

     * Run the migrations.

     */

    public function up(): void

    {

        // big thanks to https://github.com/reinink for his amazing work in https://eloquent-course.reinink.ca/

        if (config('database.default') === 'mysql') {

            DB::unprepared("

                drop function if exists natural_sort;

                create function natural_sort(s varchar(255)) returns varchar(255)

                    no sql

                    deterministic

                begin

                    declare orig   varchar(255)  default s;

                    declare ret    varchar(255)  default '';

                    if s is null then

                        return null;

                    elseif not s regexp '[0-9]' then

                        set ret = s;

                    else

                        set s = replace(replace(replace(replace(replace(s, '0', '#'), '1', '#'), '2', '#'), '3', '#'), '4', '#');

                        set s = replace(replace(replace(replace(replace(s, '5', '#'), '6', '#'), '7', '#'), '8', '#'), '9', '#');

                        set s = replace(s, '.#', '##');

                        set s = replace(s, '#,#', '###');

                        begin

                            declare numpos int;

                            declare numlen int;

                            declare numstr varchar(255);

                            lp1: loop

                                set numpos = locate('#', s);

                                if numpos = 0 then

                                    set ret = concat(ret, s);

                                    leave lp1;

                                end if;

                                set ret = concat(ret, substring(s, 1, numpos - 1));

                                set s    = substring(s,    numpos);

                                set orig = substring(orig, numpos);

                                set numlen = char_length(s) - char_length(trim(leading '#' from s));

                                set numstr = cast(replace(substring(orig,1,numlen), ',', '') as decimal(13,3));

                                set numstr = lpad(numstr, 15, '0');

                                set ret = concat(ret, '[', numstr, ']');

                                set s    = substring(s,    numlen+1);

                                set orig = substring(orig, numlen+1);

                            end loop;

                        end;

                    end if;

                    set ret = replace(replace(replace(replace(replace(replace(replace(ret, ' ', ''), ',', ''), ':', ''), '.', ''), ';', ''), '(', ''), ')', '');

                    return ret;

                end;

            ");

        }

        if (config('database.default') === 'pgsql') {

            DB::unprepared('

                create or replace function natural_sort(text)

                returns bytea language sql immutable strict as

                $f$ select string_agg(convert_to(coalesce(r[2],length(length(r[1])::text) || length(r[1])::text || r[1]),\'SQL_ASCII\'),\'\x00\')

                from regexp_matches($1, \'0*([0-9]+)|([^0-9]+)\', \'g\') r; $f$;

            ');

        }

    }

    /**

     * Reverse the migrations.

     */

    public function down(): void

    {

        if (config('database.default') === 'mysql') {

            DB::unprepared('drop function if exists natural_sort');

        }

        if (config('database.default') === 'pgsql') {

            DB::unprepared('drop function if exists natural_sort');

        }

    }

};