Details
-
Type:
Bug
-
Status:
Resolved
-
Priority:
Major
-
Resolution: Fixed
-
Affects Version/s: 1.0.1
-
Fix Version/s: 1.1.0
-
Component/s: DSL for Business Domain
-
Labels:None
-
Number of attachments :
Description
Problem
Given a not-null foreign key constraint in the database and a bi-directory one-to-many association. Mod4j now generates a configuration that causes it to be impossible to delete children (the many side of the association) .
Cause
See (17.2):
https://www.hibernate.org/hib_docs/nhibernate/1.2/reference/en/html/example-parentchild.html
And:
https://www.hibernate.org/209.html
In the Basic Collection pattern the mapping works like this:
1. The parent maps the set containing the children to the appropriate
child table as a one-to-many relationship, e.g. one parent to many
children.2. The parent marks the relationship as "inverse". This attribute says
that the parent doesn't actually update the relationship; the child
updates the relationship. We do this so that we can deal with "NOT
NULL" constraints on the child side.
DEFECT: the inverse property in the Parent.hbm.xml is FALSE and it should be TRUE.
I think due to the fact in the test application RecordShop Hibernate generates the DDL this problem does not come to light. It does, however, when using a hand-written datamodel that is set up to keep the one2many association consistent. In the RecordShop the foreign key column is NULL and in my datamodel it is NOT NULL.
Solution
Update the XPand template to generate inverse=true in case of a bidirectorional one-to-many association.
This was tested by manually changing the generated hbm.xml and running a integration test that does a cascading delete of a one-to-many association.
New 
best-practice for Hibernate and thus for mod4j
Don't use unidirectional one-to-many associations, make them bidrectional instead.
Issue Links
| This issue is superceded by: | ||||
| MODFORJ-143 | Refactor equals() and hashCode() methods in domain objects |
|
|
|
Please update the component (I cannot), it should be Domain DSL instead of Data Contract DSL.