我需要一个使用Doctrine 2的“多态关联”的具体代码示例。
让我澄清一下。我有一个实体称为Contract,一个合同可以有多个价格规则,这些价格规则可以是不同类型的类并且存在于不同的表中。我想这就是多态关联的用途,或者我错了吗?
class contract {
private $id;
private $priceRules;
}
class discountRule implements priceRule{
function calculate() {
// calculate new price after this rule
}
}
class extraSpecialRule implements priceRule {
function calculate() {
// calculate new price after this rule
}
}
未来可能会有新的价格规则类型,那么我该如何将这些规则与主实体关联并将它们存储在单独的表中?
更新:
这是我的新代码:
contract.php
namespace Entities;
use Doctrine\Common\Collections\ArrayCollection;
/**
* @Entity @Table(name="contract")
*/
class Contract {
/**
*
* @Id @Column(type="integer")
* @GeneratedValue(strategy="AUTO")
*/
private $id;
/**
*
* @Column(type="integer")
*/
private $propertyId;
/**
*
* @Column(type="integer")
*/
private $agencyId;
/**
*
* @OneToMany(targetEntity="priceRule" ,mappedBy="contract")
*
*/
private $priceRules;
public function __construct($propertyId,$agencyId){
$this->propertyId=$propertyId;
$this->agencyId=$agencyId;
$this->priceRules=new ArrayCollection();
}
public function addPriceRule(priceRule $rule){
$this->priceRules[]=$rule;
}
public function getPriceRules(){
return $this->priceRules;
}
}
pricerule.php
namespace Entities;
/**
* @Entity
* @InheritanceType("JOINED")
* @DiscriminatorColumn(name="discr" , type="string")
* @DiscriminatorMap({"discountrule"="discountRule","extradiscountrule"="extraDiscountRule"})
*/
class priceRule{
/**
*
* @Id @Column(type="integer")
* @GeneratedValue(strategy="AUTO")
*/
private $id;
/**
*
* @ManyToOne(targetEntity="contract",inversedBy="availibilityRules")
* @JoinColumn("contract_id",referencedColumnName="id")
*/
private $contract;
}
discountrule.php
namespace Entities;
/**
* @Entity
*
*
*/
class discountRule extends priceRule {
/**
*
* @Id @Column(type="integer")
* @GeneratedValue(strategy="AUTO")
*/
private $id;
public function calculatePrice(){
// calculate new price
}
}
extradiscountrule.php
namespace Entities;
/**
* @Entity
*
*
*/
class extraDiscountRule extends priceRule {
/**
*
* @Id @Column(type="integer")
* @GeneratedValue(strategy="AUTO")
*/
private $id;
public function calculate() {
// calculate new price
}
}
sampleusage.php
$contract=new Contract(1,1);
$discount=new discountRule();
$em->persist($discount);
$contract->addPriceRule($discount);
$em->persist($contract->getPriceRules());
$em->persist($contract);
$em->flush();
但是当我尝试向合同添加新规则时,我收到错误消息(致命错误:未捕获的异常'Doctrine\ORM\Mapping\MappingException',消息为“类Doctrine\Common\Collections\ArrayCollection不是有效实体或映射超类。”)
我做错了什么?