diff --git a/demodoctrine/README.md b/demodoctrine/README.md
index 26254bcc..096b3158 100644
--- a/demodoctrine/README.md
+++ b/demodoctrine/README.md
@@ -1,10 +1,12 @@
 Demo Doctrine
 =====================
 
-This module demonstrates how to use Doctrine entities in PrestaShop 1.7.7.
+This module demonstrates how to use Doctrine entities in PrestaShop 1.7.7 and 1.7.8 versions.
 
 Please note this module is an example only, not a mandatory structure.
 
+![Demo Doctrine Screenshot](demodoctrine-screenshot.png)
+
 ## Requirements
 
  1. Composer, see [Composer](https://getcomposer.org/) to learn more
diff --git a/demodoctrine/Resources/data/install.sql b/demodoctrine/Resources/data/install.sql
index aacd8421..5834c03c 100644
--- a/demodoctrine/Resources/data/install.sql
+++ b/demodoctrine/Resources/data/install.sql
@@ -1,2 +1,2 @@
 CREATE TABLE IF NOT EXISTS `PREFIX_quote` (id_quote INT AUTO_INCREMENT NOT NULL, author VARCHAR(255) NOT NULL, date_add DATETIME NOT NULL, date_upd DATETIME NOT NULL, PRIMARY KEY(id_quote)) DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE = InnoDB
-CREATE TABLE IF NOT EXISTS `PREFIX_quote_lang` (id_quote INT NOT NULL, id_lang INT NOT NULL, content LONGTEXT NOT NULL, INDEX IDX_4D76F37E85F48AC4 (id_quote), INDEX IDX_4D76F37EBA299860 (id_lang), PRIMARY KEY(id_quote, id_lang)) DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE = InnoDB
+CREATE TABLE IF NOT EXISTS `PREFIX_quote_lang` (id_quote INT NOT NULL, id_lang INT NOT NULL, content LONGTEXT NULL, INDEX IDX_4D76F37E85F48AC4 (id_quote), INDEX IDX_4D76F37EBA299860 (id_lang), PRIMARY KEY(id_quote, id_lang)) DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE = InnoDB
diff --git a/demodoctrine/demodoctrine-screenshot.png b/demodoctrine/demodoctrine-screenshot.png
new file mode 100644
index 00000000..b681aa0a
Binary files /dev/null and b/demodoctrine/demodoctrine-screenshot.png differ
diff --git a/demodoctrine/src/Entity/QuoteLang.php b/demodoctrine/src/Entity/QuoteLang.php
index 2b8eeab0..9cafded6 100644
--- a/demodoctrine/src/Entity/QuoteLang.php
+++ b/demodoctrine/src/Entity/QuoteLang.php
@@ -38,7 +38,7 @@ class QuoteLang
 
     /**
      * @var string
-     * @ORM\Column(name="content", type="string", nullable=false)
+     * @ORM\Column(name="content", type="string", nullable=true)
      */
     private $content;
 
@@ -92,7 +92,7 @@ public function getContent()
      * @param string $content
      * @return $this
      */
-    public function setContent(string $content)
+    public function setContent(?string $content)
     {
         $this->content = $content;