create offerings and its migration

src/Entity/User.php

@@ -3,6 +3,8 @@
 namespace App\Entity;
 
 use App\Repository\UserRepository;
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
 use Symfony\Component\Security\Core\User\UserInterface;
@@ -47,6 +49,16 @@ class User implements UserInterface
      */
     private $username;
 
+    /**
+     * @ORM\OneToMany(targetEntity=Offering::class, mappedBy="byUser", orphanRemoval=true)
+     */
+    private $offerings;
+
+    public function __construct()
+    {
+        $this->offerings = new ArrayCollection();
+    }
+
     public function getId(): ?int
     {
         return $this->id;
@@ -146,4 +158,34 @@ class User implements UserInterface
 
         return $this;
     }
+
+    /**
+     * @return Collection|Offering[]
+     */
+    public function getOfferings(): Collection
+    {
+        return $this->offerings;
+    }
+
+    public function addOffering(Offering $offering): self
+    {
+        if (!$this->offerings->contains($offering)) {
+            $this->offerings[] = $offering;
+            $offering->setByUser($this);
+        }
+
+        return $this;
+    }
+
+    public function removeOffering(Offering $offering): self
+    {
+        if ($this->offerings->removeElement($offering)) {
+            // set the owning side to null (unless already changed)
+            if ($offering->getByUser() === $this) {
+                $offering->setByUser(null);
+            }
+        }
+
+        return $this;
+    }
 }