原则在联接选择上返回空对象

Question

I have this function on my symfony class repository:

public function findAllByIdShop($id)
{
    return $this->getEntityManager()
        ->createQuery(
            'SELECT s, c
            FROM  AppBundle:ShopCategory s
            JOIN  s.category c
            WHERE s.shop = :shop_id
            ORDER BY c.name'
        )
        ->setParameter(':shop_id', $id)
        ->getResult();
}

The query returns the last record category (with alias c) as NULL value, if I change the select line by "SELECT s" I will get the correct results with doctrine lazyloading and I would like to avoid lazyloading.

For example if I have four categories named "c1, c2, c3, c4" in the repository query, i'll obtain c4 as null.

My class look like that (note that i'm using Many-To-One, Unidirectional relations to avoid bidirectional relations)

<?php

namespace AppBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * ShopCategory
 *
 * @ORM\Table()
 * @ORM\Entity
  */
class ShopCategory
{


    /**
     * @ORM\Id
     * @ORM\ManyToOne(targetEntity="AppBundle\Entity\Shop")
     */
    private $Shop;


    /**
     * @ORM\Id
     * @ORM\ManyToOne(targetEntity="AppBundle\Entity\Category")
     */

    private $Category;


    /**
     * Set Shop
     *
     * @param AppBundle\Entity\Shop $Shop
     * @return ShopCategory
     */
    public function setShop(\AppBundle\Entity\Shop $Shop)
    {
    $this->Shop = $Shop;

    return $this;
    }

    /**
     * Get Shop
     *
     * @return AppBundle\Entity\Shop
     */
    public function getShop()
    {
    return $this->Shop;
    }

    /**
     * Set Category
     *
     * @param AppBundle\Entity\Category $Category
     * @return ShopCategory
     */
    public function setCategory(\AppBundle\Entity\Category $Category)
    {
    $this->Category = $Category;

    return $this;
    }

    /**
     * Get Category
     *
     * @return AppBundle\Entity\Category 
     */
    public function getCategory()
    {
    return $this->Category;
    }
}

Answer 1

try this

 public function findAllByIdShop($id)
    {
        return $this->getEntityManager()
            ->createQuery(
                'SELECT s, c
                FROM  AppBundle:ShopCategory sc
                JOIN  sc.category c
                JOIN  sc.shop s
                WHERE s.<id_field> = :shop_id
                ORDER BY c.name'
            )
            ->setParameter(':shop_id', $id)
            ->getResult();
    }