Exception in thread "main" org.hibernate.PropertyValueException: not-null property references a null or transient value:

Exception in thread "main" org.hibernate.PropertyValueException: not-null property references a null or transient value: persistance.Client.prenom

at org.hibernate.engine.Nullability.checkNullability(Nullability.java:72)

This exception occurs because you have a column named prenom wich is not nullable , and you forgot to set it's value.

So to resolve this issue you must add a valuet to this property .