Doctrine - ManyToMany with custom primary key - mysql

Question

I've a unidirectional ManyToMany relation:
class Account {
/* other attributes ... */
/**
* #ORM\ManyToMany(targetEntity="App\Entity\Item")
* #ORM\JoinTable("account_items",
* joinColumns={#ORM\JoinColumn(name="account_id", referencedColumnName="id")},
* inverseJoinColumns={#ORM\JoinColumn(name="item_id", referencedColumnName="vnum")}
* )
*/
private $items;
}
What I want to do:
I would like to make the account possible to have one or more identical Item (the same identifier.). For example:
`account_id` 1, `item_id` 1
`account_id` 1, `item_id` 1
should've been allowed.
It's not possible when doctrine generates DDL query with two primary keys (account_id, item_id) and if I try to do it I got mysql duplciation entry error.
I customized migration that creates id as primary key (as only one), but I think it's not proper solution.
`id`: 1, account_id` 1, `item_id` 1
`id` : 2, account_id` 1, `item_id` 1
Do you have any?

Answer 1

Make a bi-directionnal OneToMany <=> ManyToOne relation between 3 entities.
src/AppBundle/Entity/Account.php
class Account {
/**
* #ORM\OneToMany(targetEntity="AppBundle\Entity\AccountItem", mappedBy="accounts")
*/
private $accountItems;
}
src/AppBundle/Entity/AccountItem.php
class AccountItem {
/**
* #var int
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #ORM\ManyToOne(targetEntity="AppBundle\Entity\Account", inversedBy="accountItems")
*/
private $accounts;
/**
* #ORM\ManyToOne(targetEntity="AppBundle\Entity\Item", inversedBy="itemAccounts")
*/
private $items;
}
src/AppBundle/Entity/Item.php
class Item {
/**
* #ORM\OneToMany(targetEntity="AppBundle\Entity\AccountItem", mappedBy="items")
*/
private $itemAccounts;
}
It's in fact a ManyToMany relation, but you can now add id, which will be unique, en still have duplicate entries.
Side now, you're referencing item.vnum in your annotation. Know that Symfony hate it when you don't use id.