JPA and @ManyToMany with Association Class

Hi!
I need to create a @ManyToMany relationship with another field in relation table besides the primary keys of the two main tables. How can I do that? I'm using Toplink Essentials.
Thanks.

ManyToMany relationships having an attribute can be modeled by an extra object, e.g.:
Assuming A has a ManyToMany relationship to B. Introduce an object, say AB, having:
* the extra attribute xyz
* a ManyToOne relationship A, ie. A is the "one" side, AB owns the relationship
* a ManyToOne relationship to B, ie. B is the "one" side, AB owns the relationship
* AB's primary key would be the conbination of the foreign keys to A and B

Similar Messages

UML: Rel. with association class having attrib. Are they equivalent?

Hi All, (and 1M Thanks.)
Notation:
_______________ : Bidirection
1 : cardinality One
* : cardinality many
................: I draw it to graphically shown the association class AB
Question 1: Is point 1 and 2 equivalent from the implementation perspective?
Question 2: Likewise, Is point 3 and 4 equivalent from the implementation perspective?
1.
A (1) _______________ (1) B
............|
............|
............AB (association class with an attribute)
2.
A (1) _______________ (1) AB (1) _______________ (1) B
3.
A (*) _______________ (*) B
............|
............|
............AB (association class with an attribute)
4.
A (1) _______________ (*) AB (*) _______________ (1) B

Association classes imposes that there should only be one connection between two instances, while there is no such limitation in the other case (your comparison between 3 and 4). But there probably won't be any difference between 1 and 2.

Frmf2xml and frmxml2f with property classes that have triggers

All,
I am not sure if I have a setup problem or a bug, but here goes. When I convert a form from fmb to xml (using frmf2xml) the .xml version gets created fine. When I convert back I get the following error:
Processing XML module module1_fmb.xml
Subclassing error: Check that your FORMS_PATH contains all parent modules.
Could not find exisiting sub-object KEY-CLRBLK on owner MODULE1
Could not find exisiting sub-object KEY-DELREC on owner MODULE1
Could not find exisiting sub-object WHEN-MOUSE-CLICK on owner MODULE1
Module saved as module1.fmb
The FORMS_PATH is set right etc. The problem only shows up in the following circumstances:
I have a property class in the form - the property class has a trigger - the property class is attached to the Module Property Sheet.
Looking at the XML that gets generated, it looks like the trigger information is repeated when the property class is used at form level. If i use it at block or item level it converts ok?
I can't find anything on metalink and wondered if anyone else had the issue? i.e. a functional property class with triggers used at module level.
Thanks in advance,
Bren

It's quite easy to replicate this (if anyone is interested):
1. Create a new form
2. Create a property class and call it Module_Class
3. Add a couple of triggers to the class with "Null;" in teh trigger code, say a PRE-FORM trigger and a POST-FORM trigger.
Now - if you save the module at this stage conversion works fine to/from XML/FMB.
Open the form and select the modules property sheet. Now, subclass the module using the Module_Class you created before.
Save the module.
Now - conversion from fmb to XML appears to work - but converting back fails.
Can anyone verify this?
Regards,
Bren

Windows vista and problem with association .swf files

I have win vista 32bit. Downloaded and install adobe flash player from adobe site. I have some file with .swf extension but can not get to work with adobe flash player 10.1r52. Ii can asociated ths type of file with adobe flash player. Where is the adobe flash player after installation_in which folder? Confused. Help.

Hi, The Flash files are at C:\Windows\System32\Macromed\Flash
Also, if you used IE to Install Flash Player, then in Tools, Manage add ons you also need the Shockwave Flash Object,
the ActiveX Control and it must be Enabled. This is Installed when Flash Player is Installed.
If you are using Firefox or another non-IE browser, then in the plugins, there will be a SWF (version number of Flash Player) and it must be Enabled.
Hope this helps,
eidnolb

How to translate many to many with association class

hello
I have found that there is many way to translate this to java code ,could you please tell me what do you think about this. is it right ??is it the best way ??
The relation between A and B is a bidirectional
Class A:
-idA
ClassB:
-idB
Class C:
-date
Class A {
private int idA;
private C[] c;
public A(){}
//getters and setters and other methods
Class B {
private int idB;
private C[] c;
public B(){}
//getters and setters and other methods
Class C {
private int idA;
private int idB;
private Date date;
public C(){}
//getters and setters and other methods
}thank you in advance

What do you need the IDs for? I prefer this:
Class A {
 private Set<C> cees = new HashSet<C>();
 public A(){}
 //other methods
Class B {
 private Set<C> cees = new HashSet<C>();
 public B(){}
 //other methods
Class C {
 private final A a;
 private final B b;
 private Date date;
 public C(final A a, final B b){
 this.a = a;
 this.b = b;
 //other methods
}

How to represent an association "many to many" with an association class?

I work with JPA (and TopLink essentials).
Class Person
Class Project
Association M:N between these 2 classes. A person has a function in each project she participates in.
My relational schema:
table PERSON, primary key person_id, person_name,...
table PROJECT, primary key project_id, project_name,...
table PARTICIPATION,
- primary key (person_id, project_id). person_id references PERSON and project_id references PROJECT.
- column "function".
How to write the entities Person, Project and Participation so that they map the relational schema? I don't know what to put as the "id" (@Id) of the class Participation
I know how to solve the problem by adding an attribute id (annotated by @Id) in the class Participation that would map to an id column in the table PARTICIPATION but I would like to match exactly the relational schema: the primary key of PARTICIPATION is (person_id, project_id) and not another id column.
Thanks in advance for your answers.

Thanks for your answer. I see what I have to do.
There are 2 items I don't understand in your message. My questions are beneath, inside the text of your message:
You have a m-m relationship with additional
information in the join table. To map this you need
an object representing the join table, in your case
you have chosen Participation. So you basically need
to define a 1-m from Person to Participation and a
1-m from Project to Participation (unless you only
care about access from one side).
Participation should have a 1-1 to Person and another
1-1 to Project using the two foreign key fields.I would say they are m-1 associations. But perhaps you have made a typing error?
Although TopLink allows 1-1 mappings to be used a
primary keys, the JPA Spec requires that you have
basic mappings, so you also need a personId and
projectId attribute in the Participation.I don't understand. Can you detail your answer?
I have not found the section of the JPA specification which says how to do with 2 mappings.
>
Because you will have two mappings for the same
foreign key field, in TopLink you will require to set
one of them read-only, you do this in JPA through
setting insertable and updateable on the @Column to
false.

Inheritence and association classes

I have a Person class a employee class and a manager class with employee and manager extending Person. An employee can arrange a meeting with thier manager, these classes are pretty straight forward:
class Person {
protected String firstName;
protected String surname;
public Person() {
Person p=new Person();
public Person(String firstName, String surname) {
this.firstName=firstName;
this.surname=surname;
public void setFirstName(String name) {
firstName=name;
public void setSurname(String name) {
surname=name;
class Manager extends Person {
private int office;
public Lecturer(String firstName, String surname, int office) {
super(firstName, surname);
this.office=office;
public String getFirstName() {
return firstName;
public String getSurname() {
return surname;
class Employee extends Person {
private String employee_id;
public Student(String firstName, String surname, String employee_id) {
super(firstName, surname);
this.employee_id=employee_id;
My problem comes with the association class, I want to arrange a meeting with the manager, so I need to get the Manager name and the employee name aswell as create a time slot for the meeting.
My question is how do I get the name of the employee and the name of the Manager from class Meeting, and put them in variables, the inheritance has thrown me a little because the names for both Managers and Employees are set in the super class.
Any help would be appreciated on this.

I may not quite get your question, but - if you have a class like:
public class Meeting {
    List participants = null;
    Date meetingTime = null;
    // Appropriate get/set methods
    public void addParticipant(Person attendee) {
        participants.add(attendee);
    public Person getAttendee(int attendeeIndex) {
        return (Person)participants.get(attendeeIndex);
    // and other stuff
}Then you could just add employees and managers via the addAttendee method and then retrieve them via the getAttendee method, then call getName on the Person object that you get back.
Make sense?
Lee

I have two Apple IDs - one associated with iPad and iPhone and the other associated with iMac and MacAir. I am going to lose the former e-mail address imminently and would like to associate all devices with just one ID. How do I do this? Thanks

I have two Apple IDs - one associated with iPad and iPhone and the other associated with iMac and MacAir. I am going to lose the former e-mail address imminently and would like to associate all devices with just one ID. How do I do this? Thanks

Thanks - I guess it is like there were two of me!
I bought the iPhone first and it seemed natural to link it to the (work) e-mail address which was in constant use. The iMac for home use came next and it seemed natural to use my home e-mail address, particularly as I knew by then that I would lose the work address after my imminent retirement. The same logic went for the recent puchase of the MacAir. I am not sure what happened with the iPad (also a recent purchase) - iTunes seemed to puch me towards the same ID as the iPhone.
It is not a huge problem - just makes my persona look schizoid! Otherwise very happy with everything Apple.

DBM Creation of New Vehicle and the relationship with Valuation Class

HI SAP,
I'm having problem when creating new vehicle in /DBM/VM. The Valuation Class that i use for VEHI is 4010. when i click
on save the system show valuation class 3200 not allowed for material type vehicle config. i already check my valution class
configuration, My Materia Type VEHI does not link with 3200. how do i resolve this issue ?

Commander Sauk,
From the error message it appears that valuation class tied up with your vehicle model is 3200.
Is it a very new model for which no vehicles created so far?
Can you please post accounting 1 view of material too showing valuation class as well as valuation category settings?
Please also check split valuation is correctly setup for plant you are selecting for vehicle.
check and reply with findings.
Thanks
Ritesh

ABAP Objects with Workflows / Classes and Instances

Hello,
I am currently designing a workflow using an ABAP-Objects. So far I have been been able to get my Workflow to run with my class, but I have a couple of problems:
- I am using the Function 'SAP_WAPI_START_WORKFLOW' to start other subflows, which enables me to decide which subflow to start at runtime. All of the subflows have standart importing-parameters in their containers, such as the key of my class. In each workflow I instantiate my class using a self-written method, which checks the table T_INSTANCES in my object, and then either returns the object reference to an existing instance or creates a new one. Obviously all of the subflows that I call from my main workflow should be able to find the instance. As far as I can see in their protocolls, this happens without any problems. The problem starts when I make changes to the instance. For example the changing of attributes (with setter methods) seems not to work. After the subflows are finished, in my main workflow, I do not see (with getter methods) any changes that has been made to the object. Is local persistence really limited to one workflow ?
- My second problem is basically about the workflow container in workflow protocoll. In the same workflow, I can change the attributes of my object. Nevertheless, the protocoll always show the initial attribute, even though, my task with the getter-method returns the new value of the attribute.
I appreciate any help and thanks a lot in advance.

Hello Pauls,
Thank you for your answer. I think we are misunderstanding each other. The problem occurs (I think) because my class is not a singleton class. Or am I mistaken ?
When I directly start a subflow from my main workflow, then the instance that I have created in my main workflow is also visible to the subflow. As well as the static table which actually keeps track of the instances. So, in this case the subflows finds the instance and then can use the object as is.
When I start a subflow from my main workflow using the function I mentioned above, then even though the same object key is used, there is a new instance. And the static table (I assume that you mean a static variable from type table, when you say "class table") is completely empty. In this case, my "new" instance is created which overwrites every attribute that I have set in the main workflow, before I started the subflow. More interestingly, my main workflow instantiates another new object, as soon as the subflow has finished. (I am using an event to wait for the subflow to finish.)
On the other hand, I am not quite sure that I understood your approach with refresh and how it could help me. This method is not well documented anywhere, and all of the examples that I have found are about "leave it empty"
As far as I understood, this method is called by the workflow between the steps, when an object is used. I slowly start to think that I need advanced information about Workflows and Memory Management.
Thanks a lot again. Apparently, I am the only person who came across such a problem
Greetz
G.Fendoglu

Problem with local class, static private attribute and public method

Hello SDN,
Consider the following situation:
1) I have defined a LOCAL class airplane.
2) This class has a private static attribute "type table of ref to" airplane (array of airplanes)
3) A public method should return the private static table attribute
Problems:
a) The table cannot be given as an EXPORTING parameter in the method because TYPE TABLE OF... is not supported and I get syntax errors. I also cannot define a dictionary table type because it is a local class.
b) The table cannot be given as a TABLES parameter in the method because TABLES is not supported in the OO context.
c) The table cannot be given as an EXPORTING parameter in the method defined as LIKE myStaticAttribute because my method is PUBLIC and my attribute is PRIVATE. ABAP syntax requires that all PUBLIC statements are defined before PRIVATE ones, therefore it cannot find the attribute to reference to with LIKE.
I see only 2 solutions:
a) Never ever use local classes and always use global classes so that I might define a dictionary table type of my class which I can then use in my class.
b) Make the attribute public, but this goes against OO principles, and isn't really an option.
Am I missing anything here, or is this simply overlooked so far?

Hello Niels
Since your class is local and, thus, only know to the "surrounding" application is does not really make sense to make it public to any other application.
However, if you require to store instances of your local classes in internal tables simply use the most generic reference type possible, i.e. OBJECT.
The following sample report shows how to do that. Furthermore, I believe it also shows that there are no serious inconsistency in the ABAP language.
*& Report ZUS_SDN_LOCAL_CLASS
REPORT zus_sdn_local_class.
" NOTE: SWF_UTL_OBJECT_TAB is a table type having reference type OBJECT
* CLASS lcl_airplane DEFINITION
CLASS lcl_airplane DEFINITION.
PUBLIC SECTION.
 DATA: md_counter(3) TYPE n.
 METHODS: constructor,
 get_instances
 RETURNING
 value(rt_instances) TYPE swf_utl_object_tab.
PRIVATE SECTION.
 CLASS-DATA: mt_instances TYPE swf_utl_object_tab.
ENDCLASS. "lcl_airplane DEFINITION
* CLASS lcl_airplane IMPLEMENTATION
CLASS lcl_airplane IMPLEMENTATION.
METHOD constructor.
 APPEND me TO mt_instances.
 DESCRIBE TABLE mt_instances.
 md_counter = syst-tfill.
ENDMETHOD. "constructor
METHOD get_instances.
 rt_instances = mt_instances.
ENDMETHOD. "get_instance
ENDCLASS. "lcl_airplane IMPLEMENTATION
DATA:
gt_instances TYPE swf_utl_object_tab,
go_object TYPE REF TO object,
go_airplane TYPE REF TO lcl_airplane.
START-OF-SELECTION.
" Create a few airplane instance
DO 5 TIMES.
 CREATE OBJECT go_airplane.
ENDDO.
gt_instances = go_airplane->get_instances( ).
CLEAR: go_airplane.
LOOP AT gt_instances INTO go_object.
 go_airplane ?= go_object.
 WRITE: / 'Airplane =', go_airplane->md_counter.
ENDLOOP.
END-OF-SELECTION.
Regards
Uwe

I just updated my Firefox browser to Firefox 8. I am a college student and practice with HTML and CSS for class assignments. The fonts in all my html documents are being overwritten online by your script typeface. How do I resolve this issue?

I just updated my Firefox browser to Firefox 8. I am a college student and practice with HTML and CSS for class assignments. The fonts in all my html documents are being overwritten online by your script typeface. I did not have this issue in the older version. I use an iMAC running OS10.6.8. How do I resolve this issue?

Starting with this, you have errors in your CSS code.
body {
margin-top: 0px;
margin-right: 0px;
margin-bottom: 0px;
margin-left: 0px;
color: 151515;
font-family: "Gill Sans", "Gill Sans MT", "Myriad Pro", "DejaVu Sans Condensed", Helvetica, Arial, sans-serif;
background-color: EFF5F8;
body {
margin:0;
color: #151515;
font-family: "Gill Sans", "Gill Sans MT", "Myriad Pro", "DejaVu Sans Condensed", Helvetica, Arial, sans-serif;
background-color: #EFF5F8;
font-size: 100%;
Related links:
Windows Chrome, why do my fonts look so bad? - Lee Green
css3 - Bad font rendering Chrome - Stack Overflow
Nancy O.

Part interchangeability with FFF class and FFFC - HERB material type

Experts-
Have you worked with Part interchangeability with FFF class and FFFC or HERB material type?
I am looking for cross-reference functionality for interchangeable materials from maintenance/service perspective. We have users changing manufacturer's part number as and when needed and maintaining cross-reference via classification. Maintaining SAP part number and HERS is too much data maintenance, so we are looking for simple solution.
We are in standard ECC 6.0. (No APO). I checked OSS 181764, but it doesn't help us in instructions for enhancement.
If this needs activation for DIMP or A&D, do you know enhancement for this?
Thanks for your help.
RP

Hi
I have been involved with a client who is interested to know the implementation of FFF functionality. Can you share your experience in a bit more details.
The client is interested in using parts where multiple models are available in the market and few of them are interchangeable. They would like to purchase it as an asset and then manage the inventory as non valued material. How does it work throuh the APO for forecasting and demand planning functionalities.
Thanks in advance.

Initially stating No authorization required using Adobe. When I try to change it so I can transfer downloaded books by my Nook e-reader it I get an error message stating the Adobe user name and password is associated with another computer. What gives?

When I set up Adobe reader on my computer to be able to download books from a library and then transfer to my Nook e-reader, I initially stating No authorization required using Adobe. When I try to change it so I can transfer downloaded books by my Nook e-reader it I get an error message stating the Adobe user name and password is associated with another computer. What gives?

This is pretty surprising and wierd that even Reader 10.1.1 is crashing on your system. It works pefectly for me.
Would it be possible for you to get the crash dump, and upload it, so that I can have a look at the same.
Download PROCDUMP from <http://technet.microsoft.com/en-us/sysinternals/dd996900.aspx> and extract it to a folder, say, c:\temp\procdump.exe
Open cmd prompt and type "cd c:\temp".
Launch the browser and open the PDF.
Open task manager, sort processed by name. Two AcroRd32.exe instances should have been launched. Note the PID (a small integer like 5588) corresponding to the AcroRd32.exe with the higher memory usage; this is the process that must be crashing. Note this PID.
On the cmd window, type "procdump -e -ma 5588 c:\temp\01.dmp" (replace 5588 with the actual PID of the process noted in Step 4). Procdump will now wait for the aoolication to crash. If it throws a EULA, accept it.
Perform your steps to cause the crash.
Procdump will have created a dump file at "c:\temp\01.dmp". Zip it up (since it will be 100s of MBs otherwise) and share with me.
Thanks in advance for all your help
Ankit

Hello I downloaded adobe after effect CS6, but it is not installed and asks to install Adobe Support Advisor. I turn to the site and there wrote: "The Adobe Support Advisor tool was used to analyze installer log and system information associated with inst

Hello I downloaded adobe after effect CS6, but it is not installed and asks to install Adobe Support Advisor. I turn to the site and there wrote: "The Adobe Support Advisor tool was used to analyze installer log and system information associated with installation errors. The tool has been replaced with improved installation support mechanisms. Please visit Adobe Support section for Knowledge base articles around Installation . " What do I do?

yes, I did that with helping message 3, I'd remove Cs6 only, but it did not help. The message "Failed to initialize the setup program. To identify the problem, download the program Adobe Support Advisor" repeat again =(

JPA and @ManyToMany with Association Class

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