Doctrine 2 ManyToMany cascade

问题

Is it possible in Doctrine 2 to create two objects that are many to many related and call persist only on one of them to save both?

User entity:

    /**
 * Owning Side
 *
 * @ManyToMany(targetEntity="Role", inversedBy="users", cascade={"persist"})
 * @JoinTable(name="user_roles",
 *      joinColumns={@JoinColumn(name="user_id", referencedColumnName="id")},
 *      inverseJoinColumns={@JoinColumn(name="role_id", referencedColumnName="id")}
 *      )
 */
public $roles;

Role entity:

    /**
 * Inverse Side
 *
 * @ManyToMany(targetEntity="User", mappedBy="roles")
 */
public $users;

Saving:

    $role = new Role();

    $user = new User();

$user->roles->add($role);
$role->users->add($user);

$em->persist($user);
$em->flush();

It doesn't work and trows an error "A new entity was found through a relationship that was not configured to cascade persist operations: Entities\Role@0000000004a29c11000000005c48cb75. Explicitly persist the new entity or configure cascading persist operations on the relationship."

回答1:

You should apply cascade={"persist"} to the Role entity.

Not an expert on Doctrine, but I think Doctrine checks the associated entity for cascading options.

Since you are cascading the persist from Users to Roles, it checks the Role entity if it should be persisted with cascade.

来源：https://stackoverflow.com/questions/5033825/doctrine-2-manytomany-cascade