Php 从与Doctrine2的多个关系中获取数据

我在教师表和组表之间有以下关系N:N，其中有第三个教师组表

我想列出该教师教给我的所有组（**相关**），但当我得到所有教师的返回时，

$teacher->getClasses（）

为空

这是我的代码：

教师管理员：

namespace App\Controllers;

class TeacherController extends Controller
{
    public function index()
    {
        $this->teachers = $this->model->getRepository()->findAll();
        // Bring all teachers, but does not bring their groups
        // with $teachers->getGroups()
        foreach ($this->teachers as $teachers) {
            var_dump($teachers->getGroups()); die();
        }
    }
}

namespace App\Entities;

use Doctrine\Common\Collections\ArrayCollection as ArrayCollection;

/**
 * @Entity
 * @Table(name="teachers")
 */
class Teacher
{
    /**
     * @Id @Column(type="integer")
     * @GeneratedValue(strategy="AUTO")
     **/
    private $id;

    /**
     * @ManyToMany(targetEntity="Group", mappedBy="teachers")
     **/
    private $groups;

    public function __construct()
    {
        $this->groups = new ArrayCollection();
    }

    public function setGroups($groups)
    {
        $this->groups = $groups;
    }

    public function getGroups()
    {
        return $this->groups;
    }
}

namespace App\Entities;

use Doctrine\Common\Collections\ArrayCollection as ArrayCollection;

/**
 * @Entity
 * @Table(name="groups")
 */
class Group
{
    /**
     * @Id @Column(type="integer")
     * @GeneratedValue(strategy="AUTO")
     **/
    private $id;

    /**
     * @ManyToMany(targetEntity="Teacher")
     * @JoinTable(name="teachers_groups",
     * joinColumns={@JoinColumn(name="id_group",referencedColumnName="id")},
     * inverseJoinColumns={@JoinColumn(name="id_teacher", referencedColumnName="id")}
     * )
     **/
    private $teachers;

    public function __construct()
    {
        $this->teachers = new ArrayCollection();
    }

    public function setTeachers($teachers)
    {
        $this->teachers = $teachers;
    }

    public function getTeachers()
    {
        return $this->teachers;
    }
}

教师实体：

namespace App\Controllers;

class TeacherController extends Controller
{
    public function index()
    {
        $this->teachers = $this->model->getRepository()->findAll();
        // Bring all teachers, but does not bring their groups
        // with $teachers->getGroups()
        foreach ($this->teachers as $teachers) {
            var_dump($teachers->getGroups()); die();
        }
    }
}

namespace App\Entities;

use Doctrine\Common\Collections\ArrayCollection as ArrayCollection;

/**
 * @Entity
 * @Table(name="teachers")
 */
class Teacher
{
    /**
     * @Id @Column(type="integer")
     * @GeneratedValue(strategy="AUTO")
     **/
    private $id;

    /**
     * @ManyToMany(targetEntity="Group", mappedBy="teachers")
     **/
    private $groups;

    public function __construct()
    {
        $this->groups = new ArrayCollection();
    }

    public function setGroups($groups)
    {
        $this->groups = $groups;
    }

    public function getGroups()
    {
        return $this->groups;
    }
}

namespace App\Entities;

use Doctrine\Common\Collections\ArrayCollection as ArrayCollection;

/**
 * @Entity
 * @Table(name="groups")
 */
class Group
{
    /**
     * @Id @Column(type="integer")
     * @GeneratedValue(strategy="AUTO")
     **/
    private $id;

    /**
     * @ManyToMany(targetEntity="Teacher")
     * @JoinTable(name="teachers_groups",
     * joinColumns={@JoinColumn(name="id_group",referencedColumnName="id")},
     * inverseJoinColumns={@JoinColumn(name="id_teacher", referencedColumnName="id")}
     * )
     **/
    private $teachers;

    public function __construct()
    {
        $this->teachers = new ArrayCollection();
    }

    public function setTeachers($teachers)
    {
        $this->teachers = $teachers;
    }

    public function getTeachers()
    {
        return $this->teachers;
    }
}

集团实体：

namespace App\Controllers;

class TeacherController extends Controller
{
    public function index()
    {
        $this->teachers = $this->model->getRepository()->findAll();
        // Bring all teachers, but does not bring their groups
        // with $teachers->getGroups()
        foreach ($this->teachers as $teachers) {
            var_dump($teachers->getGroups()); die();
        }
    }
}

namespace App\Entities;

use Doctrine\Common\Collections\ArrayCollection as ArrayCollection;

/**
 * @Entity
 * @Table(name="teachers")
 */
class Teacher
{
    /**
     * @Id @Column(type="integer")
     * @GeneratedValue(strategy="AUTO")
     **/
    private $id;

    /**
     * @ManyToMany(targetEntity="Group", mappedBy="teachers")
     **/
    private $groups;

    public function __construct()
    {
        $this->groups = new ArrayCollection();
    }

    public function setGroups($groups)
    {
        $this->groups = $groups;
    }

    public function getGroups()
    {
        return $this->groups;
    }
}

namespace App\Entities;

use Doctrine\Common\Collections\ArrayCollection as ArrayCollection;

/**
 * @Entity
 * @Table(name="groups")
 */
class Group
{
    /**
     * @Id @Column(type="integer")
     * @GeneratedValue(strategy="AUTO")
     **/
    private $id;

    /**
     * @ManyToMany(targetEntity="Teacher")
     * @JoinTable(name="teachers_groups",
     * joinColumns={@JoinColumn(name="id_group",referencedColumnName="id")},
     * inverseJoinColumns={@JoinColumn(name="id_teacher", referencedColumnName="id")}
     * )
     **/
    private $teachers;

    public function __construct()
    {
        $this->teachers = new ArrayCollection();
    }

    public function setTeachers($teachers)
    {
        $this->teachers = $teachers;
    }

    public function getTeachers()
    {
        return $this->teachers;
    }
}

---

在我看来，您在条令注释中没有正确引用名称空间

解决方案1：

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\ManyToMany(targetEntity="Teacher")
 * @ORM\JoinTable(name="teachers_groups",
...

或解决方案2：

use Doctrine\ORM\Mapping\ManyToMany;
use Doctrine\ORM\Mapping\JoinTable;
...
/**
 * @ManyToMany(targetEntity="Teacher")
 * @JoinTable(name="teachers_groups",
...

---

换句话说，您的注释当前被忽略。我很惊讶您的教师资源库甚至将教师类视为一个实体。

我遵循了他们自己的文档示例：

http://doctrine-orm.readthedocs.org/en/latest/reference/advanced-configuration.html

。我的实体没有问题，包括其他crud学生和具有1:1关系的类。注释还可以。除非遗漏了一些关于关系的信息。我想知道是不是在小组->教师中遗漏了

inversedBy=“groups”

。如果添加它不起作用，请在

返回$this->conn->executeQuery（$sql，$params，$types）之前，在
BasicEntityPersister:：getManyToManyStatement（）
中打印出
$sql
以查看发生了什么。