XML中的Doctrine类继承

我在尝试生成实体时遇到的错误是：

[DoctrineORMMappingMappingException]

Entity class 'Employee' used in the discriminator map of class 'ApplicationMyBundleEntityPerson' does not exist.

正在尝试的XML如下：

人

<?xml version="1.0" encoding="utf-8"?>
<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping"
                  xsi="http://www.w3.org/2001/XMLSchema-instance"
                  schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">

<entity name="ApplicationMyBundleEntityPerson" inheritance-type="SINGLE_TABLE">
    <change-tracking-policy>DEFERRED_IMPLICIT</change-tracking-policy>
    <id name="id" type="integer" column="id">
        <generator strategy="AUTO"/>
    </id>

    <discriminator-column name="discr" type="string" />

    <discriminator-map>
        <discriminator-mapping value="employee" class="Employee" />
    </discriminator-map>

    <lifecycle-callbacks/>
</entity>

</doctrine-mapping>

雇员

<?xml version="1.0" encoding="utf-8"?>
<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping"
                  xsi="http://www.w3.org/2001/XMLSchema-instance"
                  schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">

<entity name="ApplicationMyBundleEntityEmployee">
    <change-tracking-policy>DEFERRED_IMPLICIT</change-tracking-policy>
    <id name="id" type="integer" column="id">
        <generator strategy="AUTO"/>
    </id>
    <lifecycle-callbacks/>
</entity>

</doctrine-mapping>

似乎很多人不使用XML来配置他们的Doctrine实体(大多数示例都使用PHP注释),但它似乎对我来说最合乎逻辑,所以我想知道如何正确地执行它.有没有其他人有这个问题,或知道解决方案？

完整的异常跟踪如下：

Exception trace:
 () at C:SVNSymfonysymfony-sandboxsrcvendordoctrinelibDoctrineORMMappi
ngMappingException.php:187
 DoctrineORMMappingMappingException::invalidClassInDiscriminatorMap() at C:S
VNSymfonysymfony-sandboxsrcvendordoctrinelibDoctrineORMMappingClassMet
adataInfo.php:1465
 DoctrineORMMappingClassMetadataInfo->setDiscriminatorMap() at C:SVNSymfony
symfony-sandboxsrcvendordoctrinelibDoctrineORMMappingDriverXmlDriver.p
hp:98
 DoctrineORMMappingDriverXmlDriver->loadMetadataForClass() at C:SVNSymfony
symfony-sandboxsrcvendordoctrinelibDoctrineORMMappingDriverDriverChain
.php:75
 DoctrineORMMappingDriverDriverChain->loadMetadataForClass() at C:SVNSymfo
nysymfony-sandboxsrcvendordoctrinelibDoctrineORMMappingClassMetadataFac
tory.php:280
 DoctrineORMMappingClassMetadataFactory->loadMetadata() at C:SVNSymfonysym
fony-sandboxsrcvendordoctrinelibDoctrineORMMappingClassMetadataFactory.p
hp:178
 DoctrineORMMappingClassMetadataFactory->getMetadataFor() at C:SVNSymfonys
ymfony-sandboxsrcvendordoctrinelibDoctrineORMMappingClassMetadataFactory
.php:125
 DoctrineORMMappingClassMetadataFactory->getAllMetadata() at C:SVNSymfonys
ymfony-sandboxsrcvendorsymfonysrcSymfonyBundleDoctrineBundleCommandDoct
rineCommand.php:143
 SymfonyBundleDoctrineBundleCommandDoctrineCommand->getBundleMetadatas() at
C:SVNSymfonysymfony-sandboxsrcvendorsymfonysrcSymfonyBundleDoctrineBun
dleCommandGenerateEntitiesDoctrineCommand.php:77
 SymfonyBundleDoctrineBundleCommandGenerateEntitiesDoctrineCommand->execute(
) at C:SVNSymfonysymfony-sandboxsrcvendorsymfonysrcSymfonyComponentCon
soleCommandCommand.php:150
 SymfonyComponentConsoleCommandCommand->run() at C:SVNSymfonysymfony-sand
boxsrcvendorsymfonysrcSymfonyComponentConsoleApplication.php:184
 SymfonyComponentConsoleApplication->doRun() at C:SVNSymfonysymfony-sandbo
xsrcvendorsymfonysrcSymfonyBundleFrameworkBundleConsoleApplication.php:
74
 SymfonyBundleFrameworkBundleConsoleApplication->doRun() at C:SVNSymfonys
ymfony-sandboxsrcvendorsymfonysrcSymfonyComponentConsoleApplication.php:
113
 SymfonyComponentConsoleApplication->run() at C:SVNSymfonysymfony-sandbox
appconsole:11