How do I use the cascade option in Symfony2 Doctri

问题:

I'm trying to understand the cascade option in Doctrine in Symfony2.

I would like to be able to delete a child entity (and not trigger the foreign key constraint error.)

I have 3 entities:

Report

/**
* @ORM\OneToMany(targetEntity="Response", mappedBy="report")
*/
protected $responses;

/**
* @ORM\OneToMany(targetEntity="Response", mappedBy="report")
*/
protected $sms;

Response

/**
 * @ORM\ManyToOne(targetEntity="Report", inversedBy="responses")
 */
protected $report;

SMS

/**
 * @ORM\ManyToOne(targetEntity="Report")
 */
protected $report;

Now I would like to delete a Response entity but I get

SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row:
a foreign key constraint fails (mybundle.sms, CONSTRAINT FK_B0A93A77BB333E0D FOREIGN KEY (reportId) REFERENCES report (id))

Where do I use the cascade option and which option should I use (detach or remove)?

I can do a lot of trial and error to figure this out, but I was hoping for an expert explanation, so I don't overlook something.

回答1:

Try using

/**
 * @ORM\ManyToOne(targetEntity="Report", inversedBy="responses")
 * @ORM\JoinColumn(name="reportId", referencedColumnName="id", onDelete="CASCADE")
 */
protected $report;

And then update yor schema. It will add database level Cascading

回答2:

Ziumin's answer

using the onDelete option for the ORM JoinColumn

method worked when you want to delete a child item (Owning Side).

But if you want to delete a Response which is a parent item (Inverse Side), this is when cascade comes in handy. In the Report entity I added the following for each of its collections (OneToMany relationships):

Report

/**
* @ORM\OneToMany(targetEntity="Response", mappedBy="report", cascade={"remove"})
*/
protected $responses;

/**
* @ORM\OneToMany(targetEntity="SMS", mappedBy="report", cascade={"remove"})
*/
protected $sms;

Now, when I delete a Report, it removes all of its associated entries in the Response and SMS tables.

回答3:

You may also use cascade=all for update all actions.

Report

 /**
 * @ORM\OneToMany(targetEntity="Response", mappedBy="report", cascade={"all"})
 */
protected $responses;

 /**
 * @ORM\OneToMany(targetEntity="SMS", mappedBy="report", cascade={"all"})
 */
protected $sms;