Constraint « Composite « JPA Q&A

1. Creating a composite Unique constraints on multiple columns stackoverflow.com

This is my model:

class User {...}
class Book {
  User author;
  int number;
}

Every book number starts at 1 per author and increments upwards. So we'll have Books 1,2,3 by John ...

2. many-to-many mapping using composite unique constraint forum.hibernate.org

Newbie Joined: Fri Apr 30, 2010 1:09 am Posts: 1 Hi all, I have 5 tables in postgres database. CREATE TABLE tasks ( task_id smallint NOT NULL, description character varying(50), CONSTRAINT pk_task PRIMARY KEY (task_id) ) CREATE TABLE roles ( role_id smallint NOT NULL, description character varying(25) NOT NULL, CONSTRAINT pk_roles PRIMARY KEY (role_id) ) CREATE TABLE role_tasks ( role_id smallint ...

3. Composite Foreign Key that maps to Unique Constraint forum.hibernate.org

4. Declaring compoent unique (composite unique key constraint) forum.hibernate.org

I have seen a couple of questions like this go by before, but I believe the answer(2) were incorrect. In my situation, I have a 'business key', which I define as a component with three properties. This key is NOT the primary key, as we all know that is not good persistent OO design, but it indeed is a unique key, ...

5. Making composite unique constraint forum.hibernate.org

Hello, At first I would like to say that although I am new to Hibernate, I already have an impression that Hibernate rules. Now, after reading through all the documentation and FAQ, I have an unsolved domain problem. Let's say, I have a database of dudes and gangs of dudes. Each dude has a nickname that is unique in his gang. ...

6. [Annotations] Adding constraints to join with composite pk forum.hibernate.org

Newbie Joined: Mon Jul 14, 2008 5:41 am Posts: 3 Hello, I'm new to Hibernate, and so far I'm liking it very much. It makes my work easy and sound. Kudos for that. I'm trying to map a legacy database (a very old one, with some bad idiosyncrasies) using Hibernate Annotations, and I've encountered this problem: I've got a table T1 ...

7. [Annotations] Adding constraints to join with composite pk forum.hibernate.org

8. composite-id, one-to-one mapping, no constraints in database forum.hibernate.org

I also have the same problem... I tried with the approach of having a seperate class for Composite-Id.. I have one-to-one relationship between Product and Product-Id.. I have Product (PId, PDesc) as composite-key I have ProductBasic (ProductId, ProductDesc) as composite-Key Case 1: I created one Composite class which is common for both Product and ProductBasic.. class CompProductRelated{ string pid; string pdesc; ...

9. One-To-Many rel. from FK to composite unique constraint ? forum.hibernate.org

Hi all, i have used Hibernate successfully in a couple of projects but now i am lost and need help. a part of a ( unfortunately unchangeable ) db schema looks like this: service ===== tech_id ( primary_key ) service_id ( unique_constraint_1 ) service_version ( unique_constraint_1 ) ... service_details ========== tech_id ( primary_key ) service_id ( foreign_key_1 ) service_version ( foreign_key_1 ...