I've been migrating the Hiberrnate version and I've found some issues.

I had some entities like:
@Basic(optional = false)
@Column(name = "discount_price", nullable = false, precision = 10, scale = 2)
private BigDecimal discountPrice;

But in my mysql BBDD can be NULL (not checked NN). This did not throw any exception and all was working Ok in Hibernate 4. But now with Hibernate 5 I think that this is more strict or some validation class has been added to the classpath and I get:
org.hibernate.PropertyValueException: not-null property references a null or transient value : .....model.entities.Product.discountPrice

Is there any way to avoid this validation?, I have many entities and I want to avoid to check all the fields.

I think that I 've found the answer:
<prop key="hibernate.check_nullability">false</prop>
And Hibernate documentation says:
Enable nullability checking. Raises an exception if a property marked as not-null is null.
Default to false if Bean Validation is present in the classpath and Hibernate Annotations is used, true otherwise.

And is strange because I've the maven dependency:
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>5.1.2.Final</version>
</dependency>

You need to remove if the entity attribute is nullable.

The whole purpose of the attribute is to validate that the attribute is NOT NULL.

Yes, but there was no check in my Hibernate 4. There was this inconsistency and the no exception was thrown. So I guess that in H4 the check was false by default.

Thank you vlad.

The Hibernate 4 was misbehaving then.