title: JPA - delete a child from OneToMany relationship
body: <p>In a <strong>@OneToMany</strong> relationship if I want to remove a child, do I need to explicitly delete that child from parent's collection as well or just deleting the child will suffice?</p>
  
  <p>For instance, <code>Person</code> and <code>Phone</code>. Each person has many phone numbers. If I want to delete one phone number from a person is this enough:</p>
  
  <pre><code>EntityManager.remove(phone);
  </code></pre>
  
  <p>Or I need to to this beforehand:</p>
  
  <pre><code>Person.getPhone().remove(phone); 
  </code></pre>
  
  <p>Not to mention, the <strong>CascadeType</strong> is set to <strong>MERGE</strong>.</p>