mongodb unwated removal of an empty field on update

Question

Currently i run a mongo query that looks similar to the following:

$query = array(
    \'user_id\' => $this->getUserId(),
    \'name\'    => $this->g         


        

Answer 1

This is because of your $query value. It is a common beginner mistake.

Placing a whole query document into update like so:

$query = array(
    'user_id' => $this->getUserId(),
    'name'    => $this->getName()
);

Without any operators will actually REPLACE the original document with this one.

Instead to $set those fields to a new value you should use $set:

$query = array('$set' => array(
    'user_id' => $this->getUserId(),
    'name'    => $this->getName() )
);

This should give you the effect you desire.