Creating documents is a two-step process. First, we create our document and set the attribute values:

$book = new Book();
$book->setName('MongoDB with Doctrine');
$book->setPrice(45);

And then we ask Doctrine to save $book in the next flush() call:

$dm->persist($book);

We can force saving by manually calling flush():

$dm->flush();

In this example, $dm is a DocumentManager object that we use to connect to our MongoDB instance like this:

$dm = DocumentManager::create(new Connection(), $config);

Updating a document is as easy as assigning values to the attributes:

$book->price = 39;
$book->persist($book);

This will save our book MongoDB with Doctrine with the new price of 39.

Updating documents in place uses the QueryBuilder interface.

Doctrine provides several helper methods around atomic updates, as listed here:

• set($name, $value, $atomic = true)
• setNewObj($newObj)
• inc($name, $value)
• unsetField($field)
• push($field, $value)
• pushAll($field, array $valueArray)
• addToSet($field, $value)
• addManyToSet($field, array $values)
• popFirst($field)
• popLast($field)
• pull($field, $value)
• pullAll($field, array $valueArray)

update will, by default, update the first document found by the query. If we want to change multiple documents, we need to use ->updateMany():

$dm->createQueryBuilder('Book')
   ->updateMany()
   ->field('price')->set(69)
   ->field('name')->equals('MongoDB with Doctrine')
   ->getQuery()
   ->execute();

In the preceding example we are setting the price of the book with name='MongoDB with Doctrine' to be 69. The list of comparison operators in Doctrine is available in the next section on read operations.

We can chain multiple comparison operators, resulting in an AND query and also multiple helper methods, resulting in updates to several fields.

Deleting a document is similar to creating it:

$dm->remove($book);

Removing multiple documents is best done using the QueryBuilder, which we will explore further in the following section:

$qb = $dm->createQueryBuilder('Book');
$qb->remove()
   ->field('price')->equals(50)
   ->getQuery()
   ->execute();