In Doctrine schema cannot be updated while I've added new field

Question

I have two tables one is product and the other is category. I've created product first and generated the database schema through terminal. When I added the below field to product entity:

     /**
     * @ORM\ManyToOne(targetEntity="Category", inversedBy="products")
     * @ORM\JoinColumn(name="category_id", referencedColumnName="id")
     */
    protected $category;

Then I added the product field to category entity as below:

/**
 * @ORM\OneToMany(targetEntity="Product", mappedBy="category")
 */
protected $products;

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

When I type the below command in terminal:

php console doctrine:schema:update --force

It says that Nothing to update - your database is already in sync with the current entity metadata.

For final step I even dropped product and category tables and generated them via the below command:

php console doctrine:schema:update --force

And both tables were created but category_id couldn't be added.

I followed the symfony's official book. Is there something here that I've missed?

I added category_id with its meta-data manually after creating entity through shell

EDIT::

Product Entity:

<?php

namespace Acme\StoreBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * Product
 */
class Product
{
    /**
     * @var integer
     */
    private $id;

    /**
     * @var string
     */
    private $name;

    /**
     * @var string
     */
    private $price;

    /**
     * @var string
     */
    private $description;

    /**
     * @ORM\ManyToOne(targetEntity="Category", inversedBy="products")
     * @ORM\JoinColumn(name="category_id", referencedColumnName="id")
     */
    protected $category;

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

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

        return $this;
    }

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

    /**
     * Set price
     *
     * @param string $price
     * @return Product
     */
    public function setPrice($price)
    {
        $this->price = $price;

        return $this;
    }

    /**
     * Get price
     *
     * @return string 
     */
    public function getPrice()
    {
        return $this->price;
    }

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

        return $this;
    }

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

Category Entity:

<?php

namespace Acme\StoreBundle\Entity;

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

/**
 * Category
 */
class Category
{
    /**
     * @var integer
     */
    private $id;

    /**
     * @var string
     */
    private $name;


    /**
     * @ORM\OneToMany(targetEntity="Product", mappedBy="category")
     */
    protected $products;

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

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

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

        return $this;
    }

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

Answer 1

You are missing correct mapping in your yml file, your yml file should contain something like this:

Product:
  type: entity
  manyToOne:
    category:
      targetEntity: Category
      inversedBy: products
      joinColumn:
        name: category_id
        referencedColumnName: id

Read more about yaml mapping in related documentation.