field « Composite « JPA Q&A

1. JPA Composite key (all fields are notNull and PRI)

I saw that exist more then one way to map a Composite Key with JPA. But in my case is kind of different: I have a table with only 2 column:

mysql> desc mytable;
| ...

2. Mapping parent child relationship - composite key formed by fields of two objects

There are three object entities: GrandParent, Parent and Child

  • GrandParent contains grandParentId
  • Parent contains object GrandParent, parentId, some attributes, and a list of Child.
  • Child contains childId and some attributes.
There are four tables: GrandParent, ...

3. JPA 2 - Foreign key that only includes one field from a composite primary key?

I'm having trouble getting a composite primary key and foreign keys working in JPA 2/Hibernate. I'm trying to create a simple scenario with countries and provinces: Country Entity:

@Table(name = "country")
public class Country ...

4. Hibernate many to many with a composite key with one field shared on either side of the relationship

This is a conceptional example, but I do not understand how to implement this. I have tables as follows:



Which map to the following hibernate many to many relationship: Book
public class Book implements Serializable ...

5. Detached criteria on composite PK fields?

I have a table with 3 columns as primary key. Code and mapping is as follows: class for the composite key

public class CIDResultCurrentState implements Serializable
    private static ...

6. JPA: Map composite primary key with one field being foreign key

I'm having trouble getting a mapping to work with Hibernate JPA, using Spring. I'll list several code excerpts, and the end of the note has the error message I'm getting. I have two tables, "student" and "absence". the "absence" table has a composite primary key consisting of all of its columns, and one of those columns is also a foreign key ...

7. composite-id with autogenerated field

M'kay, here's the deal... I'd like to create a data object that has a composite id based off a many to one relationship and a generated id. I'm generating both the java and ddl from the mapping file. Here's a mapping I've tried, but it isn't generating the code or database structure I'd like. (Well, this one won't even autogenerate code ...

8. Suggstion needed for mapping of a composite field

Hi, My table has a field that is a concatenation of several fields. For example: "HTL34GLOBAL". It is composed of "HTL" + "34" + "GLOBAL". I have 2 questions: 1. How do I map this field into the 3 sub-fields.? 2. What's the best way to do a search on any combination of the subfields? thx tom nguyen/

9. Composite-id problem: updating instead of inserting fields

I have a table of Employees and a table of Groups. An employee may belong to any number of groups so there is a many-to-many relationship in there. Also i need the date to know when the employee got into the group, so the schema is something like this: Employee idEmployee (PK) salary dob --- Group idGroup (PK) name --- GroupEmployee ...

10. Composite Key or combining fields?

Hi there I have a DB design question, is composite key better or combining fields to get a primary key better? I believe combining fields to form a unique primary key is better but I want to hear the advice from those who have more experience in DB design. Another question, I have a client table and a client table could ...

11. updating fields in a composite key

We are using Hibernate version 2.1.2. We have an object that has a primary key composed of 2 fields and we are using a composite id object. We need to be able to: 1. Retrieve an object 2. Allow the user to update the object, including the values of the fields that comprise the primary key. 3. Save the updated object ...

13. Composite Id With No Version Field

Hi, I'm working with a legacy database in which there are no version fields. In addition, some of the tables have natural keys. This causes a problem because I cannot use the key to tell Hibernate when this is a new object and I cannot tell Hibernate to use a version. When the key is a single field I can solve ...

14. problem with date field as part of composite-id

Newbie Joined: Wed Jun 29, 2005 5:13 pm Posts: 1 Location: Herndon Hi, Please help me resolve this problem. Iam unable to retrieve records if i have date field as part of the composite-id. When I remove as part of the id, it works. But i need to have the field as part of primary key. Thanks in Advance. 1) Iam ...

15. @IdClass, composite keys, and field access

I am having trouble using Hibernate Annotations with composite keys and field access. I'll take an example out of the annotations manal. The following classes, when initialized in the session factory are throwing an UnsupportedOperationException. Code: @Entity(access=AccessType.FIELD) @IdClass(FootballerPk.class) public class Footballer { public String firstname; public String lastname; public ...

16. every field included as composite-id - massive constructor

Page 1 of 1 [ 2 posts ] Previous topic | Next topic Author Message miker Post subject: every field included as composite-id - massive constructor Posted: Wed Feb 08, 2006 6:24 am Newbie Joined: Tue Oct 25, 2005 12:28 pm Posts: 18 Location: London Dear Hibernate community, I am working ...

17. Updating a field within a composite key

18. composite id with a field which is a foreign key

I've already found the way to do it. We must use element inside the one. So if the entity looks like this: Entity{ ID id (composite-id) ... (The rest of the fields) } ID{ Class1 "field 1" Class2 "field 2" (foreign key, represents relationship between Entity and another entity) } where each "field" corresponds to a column in the ...

19. How to update one of the field in composite key

Hi, I have two fields mapped as a Composite key and my requirement is that user can update those fileds also. Currently in this case, i am deleting this record and inserting a new one, but in this way my front end part holding the old reference only so next time when i am trying to update the same record with ...

20. [SOLVED]Composite foreign key with Temporal field

Newbie Joined: Sun Aug 23, 2009 8:09 am Posts: 9 Hi everyone. I have a problem with one entity referencing a composite foreign key of another entity. I have read the chapters about it on the Manning and have googled. Hibernate accepts the initial annotations, but throws an Exceptions when trying to use the Dao to create the entity referencing the ...