Eager loading of related entity in Symfony 2

Question

There are three entities: Customer, Messages, Attachments.

The relationship between these entities is straight forward: A customer can have many messages and a messa

Answer 1

the correct code example might be like the following:

NOTE: fetch message with lazy loading, i.e. get messages with additional query proactively; as long as the messages are fetched from database, the corresponding attachments referenced to each message will be loaded automatically.

Customer

class Customer
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @ORM\OneToMany(targetEntity="Message", mappedBy="customer", fetch="LAZY")
     * @ORM\OrderBy({"createdOn" = "DESC"})
     */
    private $messages;

Message

class Message
{
    /**
     * @var int
     *
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @ORM\ManyToOne(targetEntity="Customer", inversedBy="messages")
     * @ORM\JoinColumn(name="customer_id", referencedColumnName="id")
     */
    private $customer;

    /**
     * @ORM\OneToMany(targetEntity="Attchment", mappedBy="message", fetch="EAGER")
     */
    private $attachments;

Attachment

class Attachment
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @ORM\ManyToONe(targetEntity="Message", inversedBy="attachments")
     * @ORM\JoinColumn(name="message_id", referencedColumnName="id")
     */
    private $message;