How to remove a relationship cleanly in Docrine 2? - doctrine-orm

Question

There are entities Endpoint, EndpointServerConfig, and Server:
/**
* Server
*
* #ORM\Table(
* name="server",
* indexes={
* #ORM\Index(name="fk_server_server_type_idx", columns={"server_type_id"}),
* #ORM\Index(name="fk_server_cluster_idx", columns={"cluster_id"})
* }
* )
* #ORM\Entity
*/
class Server
{
/**
* #var string
*
* #ORM\Column(name="name", type="string", length=32, nullable=false)
* #ORM\Id
* #ORM\GeneratedValue(strategy="NONE")
*
* #Groups({"export"})
*/
protected $name;
/**
* #var EndpointServerConfig[]
*/
protected $endpointServerConfigs;
}
/**
* EndpointServerConfig
*
* #ORM\Table(name="endpoint_server_config", indexes={
* #ORM\Index(name="fk_endpoint_server_config_server_idx", columns={"server_name"})}
* )
* #ORM\Entity
*/
class EndpointServerConfig
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer", nullable=false)
* #ORM\Id
* #ORM\GeneratedValue(strategy="IDENTITY")
*/
protected $id;
/**
* #var Server
*
* #ORM\ManyToOne(targetEntity="Server")
* #ORM\JoinColumns({
* #ORM\JoinColumn(name="server_name", referencedColumnName="name")
* })
*
* #Groups({"export"})
*/
protected $server;
/**
* #var Endpoint
*
* #ORM\OneToOne(targetEntity="Endpoint", mappedBy="endpointServerConfig")
*/
protected $endpoint;
}
/**
* Endpoint
*
* #ORM\Table(
* name="endpoint",
* indexes={
* ...
* #ORM\Index(name="fk_endpoint_endpoint_server_config_idx", columns={"endpoint_server_config_id"}),
* ...
* }
* )
* #ORM\Entity
* ...
*/
class Endpoint
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer", nullable=false)
* #ORM\Id
* #ORM\GeneratedValue(strategy="IDENTITY")
*/
protected $id;
}
Now I want to update an entity (e.g. Foo), that contains an Endpoint. Among other changes I want to remove the reference to the Server from the Endpoint's EndpointServerConfig. That means for the database: The endpoint_server_config.server needs to be set to NULL.
I load the Foo to a Zend\Form, disable the server and submit the changes. On the server side I unset the EndpointServerConfig#server over Foo:
/** #var Foo $myFoo */
if(! $myFoo->getEndpoint()->getEndpointServerConfig()->getServer() || ! $myFoo->getEndpoint()->getEndpointServerConfig()->getServer()->getName()) {
$myFoo->getEndpoint()->getEndpointServerConfig()->setServer(null);
}
$this->entityManager->persist($myFoo);
$this->entityManager->flush($myFoo);
It leads to an error:
An exception occurred while executing 'UPDATE server SET name = ? WHERE name = ?' with params ["", "someservername"]:
SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (`mydb`.`endpoint_server_config`, CONSTRAINT `fk_endpoint_server_config_server` FOREIGN KEY (`server_name`) REFERENCES `server` (`name`) ON DELETE NO ACTION ON UPDATE NO ACTION)
That means, Doctrine tries to UPDATE the Server, instead of just to remove the reference to it from the EndpointServerConfig. But why?
Only when I manually set endpoint_server_config.server_name to NULL (directly in the database), I can save the changes via form and Doctrine.
How to get it working?
EDIT
Just noticed, that I get the same problem on every update of the EndpointServerConfig. So not only on setServer(null), bu also when I try to set a new Server. In this case the attempts leads to the error:
An exception occurred while executing 'UPDATE server SET name = ? WHERE name = ?' with params ["newservername", "someservername"]:
SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (`mydb`.`endpoint_server_config`, CONSTRAINT `fk_endpoint_server_config_server` FOREIGN KEY (`server_name`) REFERENCES `server` (`name`) ON DELETE NO ACTION ON UPDATE NO ACTION)

Answer 1

Add following:-
cascade={"persist", "remove"}
on your relation.
#ORM\ManyToOne(targetEntity="Server", cascade={"persist", "remove"})