Doctrine Query builder，计算相关的一对多行

Posted 2023-02-24

【中文标题】Doctrine Query builder，计算相关的一对多行

【英文标题】：Doctrine Query builder, count related one to many rows

【发布时间】：2015-04-09 04:43:07

【问题描述】：

<?php
namespace Raltech\WarehouseBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Doctrine\Common\Collections\ArrayCollection;

/**
 * @ORM\Entity
 * @ORM\Table(name="warehouse_magazine")
 */
class Magazine

    /**
     * @ORM\Column(type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @ORM\Column(type="string", length=100)
     */
    protected $name;


    /**
     * @ORM\Column(type="text")
     */
    protected $description;


    /**
     * @ORM\OneToMany(targetEntity="Wardrobe", mappedBy="magazine",cascade="remove")
    */
    protected $wardrobe;


    public function __construct()
    
        $this->wardrobe = new ArrayCollection();
    

    /**
     * Get id
     *
     * @return integer 
     */
    public function getId()
    
        return $this->id;
    

    /**
     * Set name
     *
     * @param string $name
     * @return Magazine
     */
    public function setName($name)
    
        $this->name = $name;

        return $this;
    

    /**
     * Get name
     *
     * @return string 
     */
    public function getName()
    
        return $this->name;
    

    /**
     * Set description
     *
     * @param string $description
     * @return Magazine
     */
    public function setDescription($description)
    
        $this->description = $description;

        return $this;
    

    /**
     * Get description
     *
     * @return string 
     */
    public function getDescription()
    
        return $this->description;
    

    /**
     * Add wardrobe
     *
     * @param \Raltech\WarehouseBundle\Entity\Wardrobe $wardrobe
     * @return Magazine
     */
    public function addWardrobe(\Raltech\WarehouseBundle\Entity\Wardrobe $wardrobe)
    
        $this->wardrobe[] = $wardrobe;

        return $this;
    

    /**
     * Remove wardrobe
     *
     * @param \Raltech\WarehouseBundle\Entity\Wardrobe $wardrobe
     */
    public function removeWardrobe(\Raltech\WarehouseBundle\Entity\Wardrobe $wardrobe)
    
        $this->wardrobe->removeElement($wardrobe);
    

    /**
     * Get wardrobe
     *
     * @return \Doctrine\Common\Collections\Collection 
     */
    public function getWardrobe()
    
        return $this->wardrobe;
    



<?php
namespace Raltech\WarehouseBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 * @ORM\Table(name="warehouse_wardrobe")
 */
class Wardrobe

    /**
     * @ORM\Column(type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @ORM\Column(type="string", length=100)
     */
    protected $name;


    /**
     * @ORM\Column(type="text")
     */
    protected $description;


    /**
     * @ORM\ManyToOne(targetEntity="Magazine", inversedBy="wardrobe")
     * @ORM\JoinColumn(name="magazine_id", referencedColumnName="id")
     */
    protected $magazine;

    /**
     * Get id
     *
     * @return integer 
     */
    public function getId()
    
        return $this->id;
    

    /**
     * Set name
     *
     * @param string $name
     * @return Wardrobe
     */
    public function setName($name)
    
        $this->name = $name;

        return $this;
    

    /**
     * Get name
     *
     * @return string 
     */
    public function getName()
    
        return $this->name;
    

    /**
     * Set description
     *
     * @param string $description
     * @return Wardrobe
     */
    public function setDescription($description)
    
        $this->description = $description;

        return $this;
    

    /**
     * Get description
     *
     * @return string 
     */
    public function getDescription()
    
        return $this->description;
    

    /**
     * Set magazine
     *
     * @param \Raltech\WarehouseBundle\Entity\Magazine $magazine
     * @return Wardrobe
     */
    public function setMagazine(\Raltech\WarehouseBundle\Entity\Magazine $magazine = null)
    
        $this->magazine = $magazine;

        return $this;
    

    /**
     * Get magazine
     *
     * @return \Raltech\WarehouseBundle\Entity\Magazine 
     */
    public function getMagazine()
    
        return $this->magazine;
    

我的 2 个实体，我想计算每个杂志有多少衣橱相关，我必须从 querybuilder 做这个

$em = $this->get('doctrine.orm.entity_manager');
$userRepository = $em->getRepository('Raltech\WarehouseBundle\Entity\Magazine');
$qb = $userRepository->createQueryBuilder('magazine')
    ->addSelect("magazine.id,magazine.name,magazine.description")
    ->InnerJoin('magazine.wardrobe', 'wardrobe')
    ->addSelect('COUNT(wardrobe.id) AS wardrobecount')

这当然行不通。 那么，有人可以提供示例如何从查询构建器中计算这个吗？

【问题讨论】：

添加->groupBy('magazine.id') ?

我觉得应该是innerJoin，小写的“i”。

它有效，但我怎么能显示不相关（wardrobecount == 0）？

用leftJoin代替innerJoin

【参考方案1】：

总结cmets：

$qb = $userRepository->createQueryBuilder('magazine')
->addSelect("magazine.id,magazine.name,magazine.description")
->leftJoin('magazine.wardrobe', 'wardrobe') // To show as well the magazines without wardrobes related
->addSelect('COUNT(wardrobe.id) AS wardrobecount')
->groupBy('magazine.id'); // To group the results per magazine

【讨论】：

当我想计算两个不同的关系时会发生什么，例如衣柜数和洗漱用品数？

您应该能够再次进行左连接->leftJoin('magazine.toletries', 'toiletries')，然后在另一列->addSelect('COUNT(toletries.id) AS toiletriescount') 上选择计数。不过，您可能想做->addSelect('COUNT(distinct toletries.id) AS toiletriescount')，这取决于您的需要，因为它是左连接。

我比较关心group by。我想我的例子并不能说明这个问题。假设您正在计算与杂志以外的事物相关的内容。我基本上会建议使用子查询。分组依据不够灵活。在这种特殊情况下效果很好，但无法扩展。