A simple chain of 3 Entities with unidirectional ManyToOne associations and cascade = CascadeType.PERSIST to their parent entity works if every Entity has a simple id (also if they all have a sequence generator for that id).
Chain:
{{Company ---o Department ---o Employee}}
If the last Entity (most dependent) in the chain (here Employee) uses an IdClass annotation in order to reuse the id of its parent entity then:
* a) The column for the company_id in department can not be updatable = false or nullable = false
* b) If all Entity instances are new created and only Employee is persisted, then the Order of statements is:
# INSERT Department
# INSERT Employee
# INSERT Company
# Update for Department
Effects:
* The foreign key column for the Department Id inside the Employee table must be nullable.
* Unnecessary roundtrip to the database for the UPDATE statement.
Observed Behavior if company_id is not nullable:
org.hibernate.action.internal.UnresolvedEntityInsertActions logCannotResolveNonNullableTransientDependencies [^Department.java] [^Employee.java] [^Company.java] [^EmployeeId.java] [^JPAUnitTestCase.java]
WARN: HHH000437: Attempting to save one or more entities that have a non-nullable association with an unsaved transient entity.
Expected Behavior:
Foreign key column in Department can be annotated with nullable = false.
No additional UPDATE will take place.
[^Department.java] [^Employee.java] [^Company.java] [^EmployeeId.java] [^JPAUnitTestCase.java] |
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