原则DQL：4个实体之间的DQL连接

Question

So, I have this entities structure:

• User that has some Email s (more than one at the same time);
• Each Email that belongs to Domain s (if email@example.com, then I have the Domain "example.com` in the database)
• Each Domain MAY have a Profile linked to it.

Now, given a User I'd like to get all the Profiles (s)he can access (IF ANY! Maybe the Domain doesn't have a Profile ).

The Entities structure:

// User entity
use FOS\UserBundle\Model\User as BaseUser;

/**
 * @ORM\Entity
 * @ORM\Table(name="users")
 */
class User extends BaseUser
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @var ArrayCollection
     *
     * @ORM\OneToMany(targetEntity="AppBundle\Entity\Email", mappedBy="forUser")
     */
    protected $emails;

    ...
}


// Email entity
/**
 * @ORM\Entity(repositoryClass="\AppBundle\Repository\EmailRepository")
 * @ORM\Table(name="emails")
 */
class Email
{
    /**
     * @var EmailValue
     *
     * @ORM\Id
     * @ORM\Column(name="email", type="email", nullable=false, unique=true)
     */
    protected $email;

    /**
     * @var Domain
     *
     * @ORM\ManyToOne(targetEntity="AppBundle\Entity\Domain", inversedBy="emails")
     * @ORM\JoinColumn(name="domain", referencedColumnName="second_level")
     */
    protected $domain;

    /**
     * @var \MyNamespace\Bundle\UserBundle\Entity\User
     *
     * @ORM\ManyToOne(targetEntity="MyNamespace\Bundle\UserBundle\Entity\User", inversedBy="emails")
     * @ORM\JoinColumn(name="for_user", referencedColumnName="id")
     */
    protected $forUser;

    ...
}


// Domain entity
/**
 * @ORM\Entity(repositoryClass="\AppBundle\Repository\DomainRepository")
 * @ORM\Table(name="domains")
 */
class Domain
{
    /**
     * @var string
     *
     * @ORM\Id
     * @ORM\Column(type="string", nullable=false, unique=true)
     */
    private $secondLevel;

    /**
     * @var UrlValue
     *
     * @ORM\Column(name="url", type="uri", nullable=false, unique=true)
     */
    private $url;

    ...

    /**
     * Each Domain can be linked to only one Profile.
     *
     * @var Profile|null
     *
     * @ORM\OneToOne(targetEntity="AppBundle\Entity\Profile", inversedBy="domain")
     */
    private $profile;

    /**
     * Each Domain can have more than one Email.
     *
     * @var Collection
     * @ORM\OneToMany(targetEntity="AppBundle\Entity\Email", mappedBy="domain")
     */
    private $emails;

    ...
}


// Profile entity
/**
 * @ORM\Table(name="profiles")
 * @ORM\Entity(repositoryClass="\AppBundle\Repository\ProfileRepository")
 * @ORM\HasLifecycleCallbacks
 */
class Profile
{
    /**
     * @var int
     *
     * @ORM\Column(name="id", type="string", unique=true)
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="CUSTOM")
     * @ORM\CustomIdGenerator(class="AppBundle\Doctrine\IdGenerator")
     */
    private $id;

    /**
     * Each Store can have only one Domain.
     *
     * @var Domain
     *
     * @ORM\OneToOne(targetEntity="AppBundle\Entity\Domain", mappedBy="profile")
     */
    private $domain;

    ...
}

Now, given a User I'd like to get all the Profiles (s)he can access (IF ANY! Maybe the Domain doesn't have a Profile ).

I decide if a User can access a Profile if (s)he has an Email with the Domain .

So, if the User has an Email email@example.com, (s)he can access the Profile of the Domain example.com.

I know I need to join the four tables but I have no idea of how I can do such JOIN .

Can you help me?

Answer 1

Since you made all your relations bidirectionals, you can perform such a query by joining tables from the Profile one. You could use the query builder and add the following method to your ProfileRepository to perform a search based on a User instance:

public function getUserProfiles(User $user)
{
    return $this->createQueryBuilder('profile')
        ->addSelect('domain') // select the corresponding domain at the same time
        ->join('profile.domain', 'domain')
        ->join('domain.emails', 'emails')
        ->where('emails.forUser = :user')
        ->setParameter('user', $user)
        ->getQuery()
        ->getResult();
}

If you simply have access to the user ID, you can use where('IDENTITY(emails.forUser) = :userId') instead of the where clause written above.

Note: If a user have multiple emails linked to the same domain/profile, the underlying SQL query will return the same profile entry multiple times but Doctrine will collapse them to a single entry in the result set if you use getResult or getArrayResult . You will get duplicates if you use getScalarResult as described in the documentation .

---

You could also do this the other way around and join emails , domain and profile from User to be able to reach all the data from your User instance. The important part would be to use leftJoin for the profile join so that domains without profiles would still get selected. In that case, you would need to add a method to your User class to crawl the emails of the user and retrieve the corresponding profiles.