associations.md

associations

What is the ArrayCollection Stuff?
The code inside __construct() is important: The $products property must be a collection object that implements Doctrine's Collection interface. In this case, an ArrayCollection object is used. This looks and acts almost exactly like an array, but has some added flexibility. Just imagine that it's an array and you'll be in good shape.

• 一对多

    // category entity
    /**
     * Many Crops have One CropsCategory.
     *
     * @ORM\OneToMany(targetEntity="Crops", mappedBy="category")
     * @ORM\OrderBy({"id" = "DESC"})
     */
    private $crops;
    
    public function __construct()
    {
        $this->canals = new ArrayCollection();
    }
  
    public function getCrops()
    {
        return $this->crops;
    }
    // crops entity
    /**
     * One Crops have One CropsCategory.
     *
     * @ORM\ManyToOne(targetEntity="CropsCategory", inversedBy="crops")
     * @ORM\JoinColumn(name="category_id", referencedColumnName="id", onDelete="CASCADE")
     */
    private $category;
    
    public function getCategory()
    {
        return $this->category;
    }
    
    public function setCategory(CropsCategory $category)
    {
        $this->category = $category;
        
        return $this;
    }
  

• 自己对自己

    /**
     * @var int
     *
     * @ORM\Column(name="parent_id", type="integer")
     */
    private $parentId;
    /**
     * One Canal has Many Canals.
     *
     * @ORM\ManyToOne(targetEntity="Canal", inversedBy="children")
     * @ORM\JoinColumn(name="parent_id", referencedColumnName="id", onDelete="CASCADE")
     */
    private $parent;
    
    /**
     * Many Canals have One Canal.
     *
     * @ORM\OneToMany(targetEntity="Canal", mappedBy="parent")
     * @ORM\OrderBy({"node" = "ASC", "id" = "DESC"})
     */
    private $children;
  
    public function __construct()
    {
        $this->children = new ArrayCollection();
    }
  
    /**
     * Set parent
     *
     * @param Canal $parent
     *
     * @return Canal
     */
    public function setParent(Canal $parent = null)
    {
        $this->parent = $parent;
        
        return $this;
    }
    
    /**
     * Get parent
     *
     * @return Canal
     */
    public function getParent()
    {
        return $this->parent;
    }
    
    public function getChildren()
    {
        return $this->children;
    }