Understanding the @ManyToOne and @OneToMany annotations with the comment system

Let's start with the comments. Visitors to our blog should be able to react to our posts. We have to create a new Comment Doctrine entity type storing the reader's comments. Comment entities will be linked to one Post entity. One post can have many comments, and one comment is associated with a sole post.

The following E-R diagram represents the MySQL schema that will be generated using mapping information:

Creating the Comment entity class (owning side)

The Comment entity has the following four properties:

• id: This is a unique identifier of the comment

• body: This represents the comment's text

• publicationDate: This is the date of publication of the comment

• post_id: This represents the post related to the comment

Here is the first code snippet of the Comment entity, containing annotated properties. It must be placed in the Comment.php file at the src/Blog/Entity/ location.

<?php

namespace Blog\Entity;

use Doctrine...