title: ManyToOne Relationship not working in Symfony using Annotations Mapping
body: <p>I am trying to create a one to many relationship in symfony using annotations mapping. Everything seems fine but the constraint is not working. I can be able to insert data on the product table without inserting data on the supplier's table as the supplier is a super entity.
  This is my attempt:</p>
  
  <p><strong>Product.php</strong></p>
  
  <pre><code>/**
       * @ORM\ManyToOne(targetEntity="Supplier", inversedBy="products")
       * @ORM\JoinColumn(name="$supplierId", referencedColumnName="$id")
       */
      private $supplier;
      /**
       * @var integer
       *
       * @ORM\Column(name="supplier_id", type="integer")
       */
      private $supplierId;
  </code></pre>
  
  <p><strong>supplier.php</strong></p>
  
  <pre><code>/**
       * @ORM\OneToMany(targetEntity="Product", mappedBy="$supplier")
       */
      private $products;
  
      public function __construct()
      {
          $this-&gt;products = new ArrayCollection();
      }
  </code></pre>
  
  <p>After adding the above, I ran this command</p>
  
  <pre><code>php bin/console doctrine:schema:update --force
  </code></pre>
  
  <p>But the relationship is never created, please what could be wrong?</p>