OneToMany連接上的Doctrine2 QB Sementical錯誤

Question

我正在嘗試使用Doctrine2 QueryBuilder創建查詢。

    $qb = $this->getObjectManager()->createQueryBuilder();
    $qb->select( array('n', 't', 'c') )
        ->from('Application\Entity\Notification', 'n')
        ->leftJoin('n.notificationType', 't')
        ->leftJoin('n.course', 'c')
        ->leftJoin('c.studyCourses', 's');

實體課程中的相關代碼如下：

    /**
     * @ORM\OneToMany(targetEntity="StudyCourses", mappedBy="Course", cascade={"all"})
     */
    protected $studyCourses;

實體StudyCourse中的相​​關代碼如下：

    /**
     * @ORM\ManyToOne(targetEntity="Course", inversedBy="studyCourses")
     * @ORM\JoinColumn(name="Course", referencedColumnName="Id", nullable=true)
     */
    protected $course;  

現在，當我嘗試運行查詢時，出現了“”附近的語義錯誤。 我認為打印由Doctrine創建的SQL將為我提供有關此錯誤的更好信息，但實際上它是：

SELECT n0_.Id AS Id0, n0_.Timestamp AS Timestamp1, n0_.TitleHtml AS TitleHtml2, n0_.ContentHtml AS ContentHtml3, n1_.Id AS Id4, n1_.Created AS Created5, n1_.Updated AS Updated6, n1_.Name AS Name7, c2_.Id AS Id8, c2_.Created AS Created9, c2_.Updated AS Updated10, c2_.Name AS Name11, c2_.Description AS Description12, c2_.Code AS Code13, c2_.ObjectId AS ObjectId14, c2_.IsActive AS IsActive15, n0_.NotificationType AS NotificationType16, n0_.User AS User17, n0_.Department AS Department18, n0_.Study AS Study19, n0_.Course AS Course20, n0_.Category AS Category21, c2_.Language AS Language22 FROM Notification n0_ LEFT JOIN NotificationType n1_ ON n0_.NotificationType = n1_.Id LEFT JOIN Course c2_ ON n0_.Course = c2_.Id LEFT JOIN 

它在LEFT JOIN之后停止！

我們將不勝感激，因為我真的不知道自己在做什么錯，也不知道如何解決此問題。 我在互聯網上搜索了類似的錯誤，但到目前為止還沒有運氣。

Answer 1

嘗試至少選擇在select數組內在studyCourses表中形成leftJoin所需的列。 首先嘗試獲取所有內容，例如“ select（array（'n'，'t'，'c'，'s'））”。 如果您沒有選擇該列，有時會中斷。 如果這行得通，請不要獲取studyCourses表中的所有列，只需選擇select中的相關列即可形成leftJoin，例如's.id'。

希望這可以幫助。

干杯!