Question

I have been fooling with the Perl MongoDB library and have been hard pressed figuring out how to do something pretty simple.

How do I maintain the order of data fields upon an insert? My code is the following:

use MongoDB;
use MongoDB::Database;
use MongoDB::OID;


my $conn = MongoDB::Connection->new;
my $db = $conn->test;
my $users = $db->testlogwiki;


$users->insert
(
   {
     "product" => "WooHoo",
     "errcode" => "WM2001_89873",
     "solution1" => "Hit the computer.",
     "line_text" => "Inserted in Perl too"
   }
);

When I go back and look up in my MongoDB how the record has been inserted it looks like this:

db.testlogwiki.find([criteria that finds it]).pretty();

"_id" : ObjectId("4fc62c2900ece6040c000000"),
"solution1" : "Hit the computer.",
"product" : "WooHoo",
"errcode" : "WM2001_89873",
"line_text" : "Inserted in Perl too"

That’s not the order I want…how do I make it the order I want?

Answer 1

Both Perl and Mongo’s BSON hashes are unordered by definition. If you need to order properties in some way, you must keep track of it yourself.