How can I use 'foreign key' on doctrine?

Question

I am making the lesson administration system on symfony2 and doctrine

I am confused to use foreign key in doctrine.

/Entity/User.php

class User extends BaseUser
{
 /**
 * @ORM\Id
 * @ORM\Column(type="integer")
 * @ORM\GeneratedValue(strategy="AUTO")
 *@ORM\OneToOne(targetEntity="Acme\UserBundle\Entity\Lesson", inversedBy("teacher"))
 */
 protected $id;
 .
 .
}

/Entity/Lesson.php

class Lesson
{
 /**
 * @var integer
 *
 * @ORM\Column(name="id", type="integer")
 * @ORM\Id
 * @ORM\GeneratedValue(strategy="AUTO")
 */
 private $id;
 /**
 *
 * @ORM\OneToOne(targetEntity="Acme\UserBundle\Entity\User", inversedBy("id"))
 * @ORM\JoinColumn(name="user_id", referencedColumnName="id")
 */
 private $teacher;
 .
 .
}

Each 'Lesson' has one teacher registered in User.php.

How can I write annotation for this purpose?

I am also planning that each Lesson has multiple students from /Entity/User. How can I write annotation for this purpose? (ManyToMany?)

I have researched ,but I couldn't find good documents for doctrine annotation.

Answer 1

Here some cheat sheets for doctrine annotations : link

For your problem, you need to define your variables in each side of your associations.

In Lesson.php :

/**
 * @ORM\OneToOne(
 * targetEntity="Acme\UserBundle\Entity\User", 
 * inversedBy="lessons*removethis : name of the variable in user.php*"
 * )
 * @ORM\JoinColumn(name="user_id", referencedColumnName="id")
 */
private $teacher;

In User.php :

/**
 * @ORM\OneToOne(
 * targetEntity="Acme\UserBundle\Entity\Lesson", 
 * mappedBy="teacher*removethis : name of the variable in lesson.php*"
 * )
 */
private $lessons;

And yes, ManyToMany is good for the purpose your are looking for :)

• whitebear: Thanks.GreenLeaf it works well for my purpose, The given link is useful as well.
• deltree: the link gives me a 404
• Pierrickouw: I updated the link. Here is the complete link : elao.com/fr/blog/symfony-2-doctrine-2-cheat-sheets
• Wes H: Updated link is dead.