我有这2个类，它们之间有ManyToMany关联:Nursery.phpnamespaceVS\CrmBundle\Entity;useDoctrine\Common\Collections\ArrayCollection;useDoctrine\ORM\MappingasORM;/***Nursery**@ORM\Table(name="Nursery")*@ORM\Entity(repositoryClass="VS\CrmBundle\Repository\NurseryRepository")*/classNursery{/***@varint**@ORM\Column(nam