Why the delete() method of Phalcon\Mvc\Collection in the MongoDB collection may not work?

Question

I inserted three documents to mongoDb collection. I want to delete a document from collection.:

It is mongoDB model:

use \Phalcon\Mvc\MongoCollection;

class AutoSnippet extends MongoCollection
{
  public $name;
  public $snippets = [];

  public function onConstruct()
  {
    $this->setSource('AutoSnippet');
  }

  public function initialize()
  {
    $this->setConnectionService('mongodbTracker');
    $this->getConnection()->selectCollection('AutoSnippet');
  }
}

Both of them work successfully.

1)

$snippet = AutoSnippet::findById("5e80a9d2577d257fe9703314");

2)

$snippet = AutoSnippet::findFirst([[
      '_id' => new MongoDB\BSON\ObjectID("5e80a9d2577d257fe9703314")
    ]]);

but delete() method doesn't work:

$snippet->delete(); // returns true

delete() method returns true but document with id "5e80a9d2577d257fe9703314" is still there.

Answer 1

The problem was in the name of the collection. The document was not deleted due to the fact that I named the collection in uppercase. I changed the name of the collection to "auto_snippet" and the removal worked.