bug #4506 SetDescription required on Product entities (yearofthegus)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #4506).

Discussion
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SetDescription required on Product entities

Doctrine sets columns to NOT NULL by default. The code in the example throws an exception without the fix.

Commits
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bb085da SetDescription required on Product entities

book/doctrine.rst

@@ -1105,6 +1105,7 @@ Now you can see this new code in action! Imagine you're inside a controller::
             $product = new Product();
             $product->setName('Foo');
             $product->setPrice(19.99);
+            $product->setDescription('Lorem ipsum dolor');
             // relate this product to the category
             $product->setCategory($category);