Creating a perl delete statement with MongoDB

[e0s]

I am having difficulty creating a perl MongoDB delete statement that will select from EITHER one table or another, depending on the TYPE of input from the user. Let's say the databases are $FRUITS and each fruit is categorized into tables either by their 'fruit_names' or unique 'fruit_ids'

Let's say the user wants to delete an entry from the fruit_names table, how do I configure my perl code so that it can differentiate between one input versus another?

I've searched cpan.org and found some MongoDB documentation on delete_one and delete_many but I haven't been able to figure out how I would create a delete_one statement that would pull from either one table or the other, depending on the user's input.

I am a novice with perl still and I've never used MongoDB before, i've been really stuck on this for a while so any help would be greatly, greatly appreciated.

[poj]

Not sure why you want to separate a fruit NAME from it's ID by using 2 collections. Maybe this demo will help you explain.

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

# connect to database
my $client = MongoDB->connect( 'mongodb://localhost:27017' );
my $db = $client->get_database( 'test' );
$db->drop; # start with empty database

# insert some test data
my @fruits = qw(apple banana cherry damson elderberry fig grape 
                kiwi mango orange pear raspberry strawberry 
                tangerine ugli watermelon);

my $fruits = $db->get_collection('fruits');

my $id = 1;
for (@fruits){
  # put ID and NAME in same collection
  $fruits->insert_one({ uid => "$id", name => $_}); 
  ++$id;
}

# show table and get user input
my $entry;
while ($entry ne 'q') {
  my $all_fruits =  $fruits->find;
  while (my $doc = $all_fruits->next) {
    printf "  %2s %s\n",$doc->{'uid'},$doc->{'name'};
  }

  print "Enter ID or Name (q to quit) > ";
  chomp($entry = <STDIN>);
  
  # use OR for either ID or Name
  my $res = $fruits->delete_one( 
    { '$or' => [ {uid=>$entry}, {name=>$entry} ] } 
  );
  printf "\n[$entry] %d records deleted \n",$res->deleted_count;
}

poj

[e0s]

thank you so much, that's actually really helpful.

[Theodore]

How would you differentiate between one input versus another?
For example, if you expect all names to be strings and all ids to be integers, you could use looks_like_number from Scalar::Util to decide if the input is a name or an id and delete from the corresponding table collection.

[thanos1983]

Hello eOs,

Welcome to the monastery. Please read How do I post a question effectively? and also as you said MongoDB::Tutorial/Updating Documents find the syntax $users->delete_many({"name" => "Joe"});.

We can not help you without seeing the minimum amount of code and effort.

Hope this helps, BR.

[e0s]

definitely forgot to post my code. sorry.

at this point i've tried creating a subroutine that is attempting to do this:

sub delete_thefruits

my $collection;
my $criteria;

for (ref $entry){ ## i think this will check for the type being input 
+by the user
when ('fruitdb::name') {
$collection = $FRUIT_NAMES;
$criteria->(name) = $entry->{data}{name};

If i create a similar function to the above, another one which only deals with the fruitIDs table, would perl understand to differentiate between the two?? or would I need to illustrate that programmatically?

$collection-> remove(criteria); ## this will hopefully eventually remo
+ve one entry whether it's fruit name or fruitID
}

[Theodore]

for (ref $entry){ ## i think this will check for the type being input 
+by the use

No, it will not.

[thanos1983]

Hello again eOs,

What I would do in your case is try to create a minimal working example for everyone here to play. For example, create db, insert data, then retrieve data, delete and retrieve again.

It is really difficult to guess what is returned and what it should be deleted (at least to me). You have the code in you node and you can execute it at any time but we do not have it, so guessing is not the best way to proceed.

Help us to help you, BR.