Question

构建查询以选择没有相应N个实体的M个实体将使用以下查询返回错误：

return $this->getEntityManager()
                ->createQuery(
                        'SELECT p FROM VolVolBundle:Opportunity p '
                        . 'LEFT JOIN VolVolBundle:Volunteer v'
                        . 'WHERE v.id is null   '
                        . 'ORDER BY p.organization ASC'
                );

返回错误：

预期的Doctrine \ ORM \ Query \ Lexer :: T_WITH，得到'v'

然而，以下SQL语句返回非空结果集：

select o.id from opportunity o
left outer join opportunity_volunteer ov on o.id = ov.opportunity_id
left outer join volunteer v on ov.volunteer_id = v.id
where ov.id is null;

其中opportunity_volunteer是链接表

机会实体关系定义

/**
 * @var \Doctrine\Common\Collections\Collection
 *
 * @ORM\ManyToMany(targetEntity="Volunteer", inversedBy="opportunities", cascade={"persist"})
 * @ORM\JoinTable(name="opportunity_volunteer",
 *      joinColumns={@ORM\JoinColumn(name="opportunity_id", referencedColumnName="id")},
 *      inverseJoinColumns={@ORM\JoinColumn(name="volunteer_id", referencedColumnName="id")}
 *      ))
 */
protected $volunteers;

public function addVolunteer(\Vol\VolBundle\Entity\Volunteer $volunteer) {
    $volunteer->addOpportunity($this);
    array_push($volunteers, $volunteer);
}

public function getVolunteers() {
    return $this->volunteers;
}

志愿者实体关系定义

/**
 * @var \Doctrine\Common\Collections\Collection
 *
 * @ORM\ManyToMany(targetEntity="Opportunity", mappedBy="volunteers")
 */
protected $opportunities;

public function addOpportunity(\Vol\VolBundle\Entity\Opportunity $opportunity) {
    array_push($opportunities, $opportunity);
}

public function getOpportunities() {
    return $this->opportunities;
}

Answer 1

从DQL docs读取，您应该使用WITH而不是WHERE来限制连接。在文档中搜索代码段“通过附加条件限制JOIN子句”。我想它应该是这样的：

return $this->getEntityManager()
    ->createQuery(
            'SELECT p FROM VolVolBundle:Opportunity p '
            . 'LEFT JOIN VolVolBundle:Volunteer v'
            . 'WITH v.id IS null   '
            . 'ORDER BY p.organization ASC'
    );

但这并未经过测试。

Answer 2

最终的解决方案是创建1：n：1关系，消除中间的“隐形”实体。这样就可以在关系中添加字段。因此，除了在连接之前确保每行以空格字符结束之外，还需要重写查询。它现在可以根据需要找到空结果：

    return $this->getEntityManager()
        ->createQuery(
                'SELECT p FROM VolVolBundle:Opportunity p '
                . 'LEFT JOIN VolVolBundle:OpportunityVolunteerEmail e '
                . 'with p = e.opportunity '
                . 'where e.opportunity is null'
                . 'ORDER BY p.organization ASC'
        )->getResult();

查询m = n关系n = null - 返回Lexer错误

机会实体关系定义

志愿者实体关系定义

2 个答案: