ADF BC: Many-to-Many Insert

Hi :)
I have a many-to-many relationship ( person has many cars and cars can have many persons)
Now i wanted to insert a new car for a given person.
So i dragged my personview->carView form and readonly table.
It inserts the new car. But the middle table is not changed.
Why?

At row creation time, a view link handles the job of filling in the current value of the respsective foreign key attributes from the current row of the master view. If you have multiple master view objects using multiple view links, then each of them will populate their respective foreign key values. If this is not what you want, then the alternative I suggested that does not use mutlple-master view objects instances would be the way to go.
I think the simplest thing for you to do is the following:
(1) Person entity associated to PersonCar entity (1-*)
(2) Car entity associated to PersonCar entity (1-*)
(3) Create a PersonView based on Person entity
(4) Create a PersonCarView based on PersonCar intersection entity, using a secondary Car entity as a reference to display the name of the car
(5) Create a CarLookupView based on the Car entity (this will be used to present a list of valid cars to pick when adding a new car for a person
If your PersonEditPage needs to display the current list of cars assigned to that person, then it would show the details from the CarView.
To add a new car for a person, you create a new row in the CarView that is the detail of the current row in the PersonView.
The "add a new car for a person" page, would have a dropdown list based on the results of the "CarLookupView" as its valid choices (and it's personId would be filled in automatically from the view link.
I think this would be the simplest way to address your use case. In practice, rather than using a many-to-many view link, its using just a single view link from PersonView to PersonCarView, and the PersonCarView references the related information about the car using a reference entity usage (which translates to a join in the automatically created SQL for your view object with reference information).

Similar Messages

Many-to-Many in ADF

Hello:
Thanks for looking this post. I have a rookie question, but I'm not finding alot of info regarding this.
Say I have two tables: Teachers and Students and there is a many-to-many between Teachers and Students. So we create a third table called Classes and create two one-to-many relationships.
The Question is how do we do this in ADF? On the screen, I'd like to show Teachers, Students and Classes and have their navigation all coordinated. I would also like to create the association if I insert a new teacher or student. (The association would be an insert into the intersection table Classes for the primary key of teachers and primary key of students) What is the best way to accomplish all of this in the GUI? Got any ideas? Also can you point me to the correct location in the technical docs?
Thanks for the Help.
Don

this will help http://mjabr.wordpress.com/2011/05/21/how-to-implement-many-to-many-association/

ADF-Newbie.How can I create a many-to-many row from an action method?

Hi all,
First of all, this is my scenario:
- JDeveloper 10.1.3.0.4
- My application is running ADF + Faces + Toplink + EJB Facade
- My database model includes some many-to-many relationships and some one-to-may relationships.
I have developed several ADF pages displaying some CRUD operations over my master tables and my master-detail tables without any problem.
I am now trying to implement some CRUDs over my many-to-many relationship tables.
Lets call the tables involved as master1, master2, and relationship (the many-to-many table)
Because usability reasons, my user wants me to implement an interface where he can:
-Select a row from the master1 table
-Select a row from the master2 table
-Click a button called "Create relationship"
I need to implement the code inside the action button to add my new record on the relationship table, and honestly, I have not found any clue.
Please, give me some directions to solve my problem.
Thank you in advance for your help...

The key here is to work with the intersection table for your MtM relationship.
The way I do it, is to have the user view Master Table I, and click on the add Relationship button, this button is a link to a add form for the Intersection Table. On the Add form, the MasterTable 1 Id is already filled in and I hide it. I then setup MasterTable 2 as an LOV on the page. The used selects the item from the LOV and clicks on the commit button. I refresh my many-to-many view and all is grand.
Using ADF/JSF, I have made it even nicer by turning the add relationship page into a dialog page, that way the user can see the previous page while adding the new relationship.
Kelly

Many-to-Many relation sample in ADF

I have a requirement to implement a screen
Three tables 1) Users 2) Access 3) Documents
The Access table contains both the references DocId and UserId and acts as the intersection table.
Users table is related to Documents through the Access table which acts as the intersection table and vice versa. I need to create a screen gui which will show all the documents a user has. Secondly also show all the users who has permission to a particular document. Is there any sample adf application which implements a simple many-to-many relation.
I am planning to create three entity objects - UsersEO, AccessEO, DocumentsEO
two view objects - UsersVO and DocumentsVO
one view link -UsersDocumentVL
Also which GUI components is best suited to address this. How many Entity Objects, View Objects and View Link should I create. Any simple sampe will help.
Regards
Thomas

Thomas,
There are of course many ways to implement your requirement. Try this exercise... forget about ADF for a moment; put your computer away (well, finish reading this first ;) ). Grab a pencil and paper.. assuming you could do anything, how would you like the screen to work? Draw it out on a piece of paper and describe how it works. You've just created a rudimentary specification. Now, come back to this thread and describe your specification - perhaps then we can help you implement your spec using ADF (or at least tell you "not possible" and describe why).
Best,
John

[ADF] Adding/deleting entries in a many-to-many relationship

I am using JDeveloper 10.1.3 and the ADF BC / ADF Model / ADF Faces / JSF technology stack.
For this question, I am using the SRDemo application as an example, specifically the many-to-many relationship between USERS and PRODUCTS (the Staff Expertise relationship), outlined in red in this schema diagram: Image Link
Users may have any number of product expertise areas and many users may have the same product expertise area. For the purposes of this example I have added two reference fields from the PRODUCT table into the ExpertiseAreas VO (Name and Description), outlined in red in this data control palette section: Image Link
I have created a page which shows the details of a user (1), along with a table showing the expertise areas the user has (3), and a table of all the products available (2), numbered on this design page: Image Link and corresponding to the numbered data controls on this data control palette section: Image Link, where 1 is rendered as an ADF Read-only Form, 2 is an ADF Read-only Table with a tableSelectMany element in the selection facet, and 3 is also an ADF Read-only Table.
What I am trying to do is have the tableSelectMany element reflect which of the products are linked to the current user in the expertise areas relationship (by having the checkbox for currently linked products checked), and when you check or uncheck a product's checkbox, it should add or remove the row in the EXPERTISE_AREAS intersection table, respectively (asume for this example that there are default values for Expertise Level and Notes).
So far I have been following the process used in section 19.8 of the ADF Developer's Guide for Forms/4GL Developers, which describes how to set up a selectManyShuttle which implements the adding and deleting functionality. So I have a Client Interface method in the Application Module, updateSkillsForCurrentStaff (described in section 10.6.7.2), and I have a selection listener for the assignment table in the backing bean for the page, which calls the updateSkillsForCurrentStaff method:
public void selectionChanged(SelectionEvent event)
BindingContainer bc = getBindings();
DCIteratorBinding productsIB = (DCIteratorBinding)bc.get("ProductListIterator");
Set keys = getTable1().getSelectionState().getKeySet();
Iterator iter = keys.iterator();
List productIds = new Vector();
while (iter.hasNext())
    String product = ((Key)iter.next()).toStringFormat(true);
    productsIB.setCurrentRowWithKey(product);
    ViewRowImpl productRow = (ViewRowImpl)productsIB.getCurrentRow();
    Number productId = (Number)productRow.getAttribute("Id");
    productIds.add(productId);
OperationBinding ob = bc.getOperationBinding("updateSkillsForCurrentStaff");
Map pm = ob.getParamsMap();
pm.put("productIds", productIds);
ob.execute();
All of this works, but I can't work out how to link the selection state of the assignment table to the expertise areas that are linked to the user. Also I think the method listing above must be a bit of a hack, but I don't know enough about this to know if there's an easier way of doing it.
Any help is appreciated.

Have a look at this example I cooked up for you.
http://radio.weblogs.com/0118231/2006/10/03.html#a739
It might not be the first way one thinks to implement something, but it illustrates a very interesting, model-centric approach to the problem you propose.
My feelings won't be hurt if you prefer a more view-centric approach, but I wanted to illustrate what was a maximally-model-centric solution (in fact, which doesn't even require a backing bean!) If you like a more view-centric approach, I can help you figure out what's wrong with your key-handling above. For one, I would probably start by passing the Set of Key's directly to the middle tier application module method to eliminate client-side code.
Check it out and let me know what you think. Try it directly in the Business Components Tester to appreciate one of the benefits a model-centric solution can bring.

Inserting with many to many relationship

db and dev 10g rel2 ,
hi all ,
an application for a laboratory ,( patients and tests)
i think the relation here is (many to many) , because each patient can have multiple tests, and each test can
have multiple patients .
what tables should i create ?
and finally i should have a block to insert data for patients , and it should have
the name of the patient and the test he is doing .
so what tables should i create , and the block for the data entry will be based on which table ? or tables ?
thanks a lot

Hi
First i do strongly recommend collecting reports & forms papers which r filled out by Mrs employees & patients then u stay to decide by ur pen & formalize what r the data required & what type of relationship need to be contracted from scratch off course many modifications Will occure by it Will be easier to modify on papers.
Then my guess is u.Will need tables for employees , Patients ,Labs & Analysis Types
Employees & Patients fields in a table r common in ;name, id,address,birthday or age ,
etc.
Labs table is needed if only u have many labs types ...
Analysis Types table is listing...
Analysis_id , Analysis_name& comments if any...
Actual_Analysis table which Will have many pk is from all previous tables e.g.
employees_id,Analysis_id, Patient_id,Lab no
,Analysis_date,Delivery_date,
Analysis time , Delivery or due time.
Status +-- A flag Which indicates ethe delivery status done or not
Deposit
way payment -- can have a table for it.
total cost
taxes
etc.
--========
All payments affairs could have a table or more for it
hope it.helps as a start.
Amatu Allah

Many-to-many association: inserting in the detail table fails

I'm using jdeveloper 11g and configured the many-to-many association as described in the documentation, so I have accessors in both directions, with composition association and a many-to-many link view. Using the business component browser, the link view works for viewing the data in both directions, as one would expect, however inserting in the detail table fails as follows: the key of the master table is the new value of the detail table's key column instead of the intersection table's foreign key column. Is this a known problem, or is there something I have done wrong?

If your m-m join table has additional fields there best solution is normally to define a class for the join table.
i.e.
beforeProgram
-m-m-> Assumption
Assumption
-m-m-> Program (optional/read-only)
-> after
Program
-1-m-> ProgramAssumptionAssociation (private-owned)
ProgramAssumptionAssociation
-1-1-> Program (pk)
-1-1-> Assumption (pk)
- createByUser
- etc.
Program
-1-m-> ProgramAssumptionAssociation (independent/optional)
You could also enable batch-reading or joining on the 1-1 relationship to read the target objects efficiently.

How many ways to insert data in the R/3 database

hi
abappers,
could u pls tell me for this question.

Hi Basha,
There are many ways to insert data in the R/3 database.
Based on lot of factors, it will be decided which option to use.
For example:
1. Through a BDC ABAP program
2. Through LSMW tool
3. Through IDOCS using ALE or EDI
4. Through ABAP program using insert/modify statement
5. Manually creating entres in the table
6. Using transaction code SM30 (Maintain table Views)
Hope this helps.
Please reward if useful.
Thanks,
Srinivasa

Insert/delete many to many join in 9.0.3

Can anyone tell me a good way to create/delete an intersection row in a many to many relationship? I can do it programmatically in the client, but I'd rather have the middle tier view object or application module handle the code. Currently I'm creating a JClient application but later I will be putting the application in a browser. I don't want to rewrite the code every time I change my client application.
Thanks

I forgot to mention that I'm using the BC4J framework.
Mike

Many to Many set up

Hey guys long time no hear :)
I have a conceptual problem (Using Jdeveloper 11g, with ADF Business Components) that I was hoping you could advise me with. I have 3 tables. Tech_Equipment, Terminal_Type, and Equipment_Terminal. As you may have already guessed they are in a many to many relationship with Equipment_Terminal serving as the intersection table. I have now just started doing the CRUD forms for all my tables and have left this for last.
What I wanted to do was create an af form to somehow do this but I am not sure how. I want the user to be able to add a Tech_Equipment, and Terminal_Type and for the Equipment_Terminal to automatically take from those 2 tables.
I was thinking of creating a 2 forms one for adding Tech_Equipment, one for Adding_Terminals, and a third for the Equipment_Terminal table, where the primary key would be auto generated and read only from a sequence, and 2 LOVs (choice lists) which would be based on primary keys from the other 2 tables (therefore enabling to user to only choose already existing Tech_Equipment, and Type_Terminal).
The problem I see is that Tech_Equipment has a foreign key Terminal_Type_ID which I made an LOV based on Terminal_Type name. So whenever you want to insert a Tech_Equipment you have to choose the Terminal_Type. This creates a problem when you have more than one Type_of_Terminal, and I want to show it to the user, as the choice list will only let me choose the one.
Any help and advice are appreciated

Have you checked this sample:
http://blogs.oracle.com/smuenchadf/examples/#89
Regards,
DEMR

Hibernate - Spring - problem with mapping (many-to-many)

Hello,
I want to map the following situation. I have a table called EDUCATION and a table called SCHOOLS. Between those tables I have an associative table called EDUCATION_SCHOOLS. The (usefull) fields:
EDUCATION:
id (long) - PK
name (varchar)
versionNr (long)
SCHOOLS:
id (long) - PK
name (varchar)
versionNr (long)
EDUCATION_SCHOOLS:
id (long) - PK
education_id (long) (FK to EDUCATION.id)
school_id (long) (FK to SCHOOLS.id)
name (varchar)
versionNr (long)
Their is a Unique Constraint between EDUCATION_SCHOOLS.education_id and EDUCATION_SCHOOLS.school_id.
What I want to be able to do:
EDUCATION: select, update, insert
SCHOOLS: select, update, insert
EDUCATION_SCHOOLS: select, update (only the non-FK fields), insert
I never want to delete anything in those tables. (and it's never ever going to be an option either)
Hibernate version:
Hibernate-Version: 3.0.5
Mapping documents:
Education:
<hibernate-mapping>
     <class name="##.Education" table="EDUCATION">
          <id name="id" column="ID" type="java.lang.Long">
               <generator class="sequence">
                    <param name="sequence">EDUCATION_SEQ</param>
               </generator>
          </id>
          <version name="versionNr" column="VERSIONNR" type="long"/>
          <property name="name" column="NAME" type="string" />
        <set name="SCHOOLS" table="EDUCATION_SCHOOLS">
            <key column="EDUCATION_ID" />
            <many-to-many class="##.Schools" column="SCHOOL_ID" lazy="false" />
        </set>
</hibernate-mapping>
Schools:
<hibernate-mapping>
     <class name="##.Schools" table="SCHOOLS">
          <id name="id" column="ID" type="java.lang.Long">
               <generator class="sequence">
                    <param name="sequence">SCHOOLS_SEQ</param>
               </generator>
          </id>
          <version name="versionNr" column="VERSIONNR" type="long"/>
          <property name="name" column="NAAM_NAME" type="string" />
        <set name="educations" table="EDUCATION_SCHOOLS" inverse="true" cascade="none">
            <key column="SCHOOL_ID" />
            <many-to-many class="##.Schools" column="SCHOOL_ID" lazy="proxy"/>
        </set>
</hibernate-mapping>
Education_schools:
<hibernate-mapping>
<class name="##.EducationSchools" table="EDUCATION_SCHOOLS">
           <id name="id" column="ID" type="java.lang.Long" unsaved-value="0">
               <generator class="sequence">
                    <param name="sequence">SEQ_EDUCATION_SCHOOLS</param>
               </generator>
          </id>
          <version name="versionNr" column="VERSIONNR" type="long" />
          <many-to-one name="education" class="##.Education" cascade="none" lazy="proxy"
                       column="EDUCATION_ID" not-null="true"/>
        <many-to-one name="schools" class="##.Schools" cascade="none" lazy="proxy"
                    column="SCHOOL_ID" not-null="true"/>
</hibernate-mapping>
Name and version of the database you are using:
Oracle XE 10g
I am able to:
EDUCATION: select, insert, update
SCHOOLS: select, insert, update
EDUCATION_SCHOOLS: select
Problems:
EDUCATION_SCHOOLS: when I try to insert, I sometimes get unique constraint violations. (when I should get them, thus I'm trying to insert something that already exists .. but how do I stop Hibernate from Inserting?)
EDUCATION_SCHOOLS: when I try to update, sometimes it works, but often I get:
23:03:55,484 [http-8081-1] ERROR be.vlaanderen.lne.vea.epb.ui.struts.EpbExceptionHandler - org.springframework.orm.hibernate3.HibernateOptimisticLockingFailureException: Object of class [##.EducationSchools] with identifier [null]: optimistic locking failed; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [##.EducationSchools#<null>]
ex.getMessage() Object of class [##.EducationSchools] with identifier [null]: optimistic locking failed; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [##.EducationSchools#<null>]
org.springframework.orm.hibernate3.HibernateOptimisticLockingFailureException: Object of class [##.EducationSchools] with identifier [null]: optimistic locking failed; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [##.EducationSchools#<null>]
Caused by: org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect):As you can see from the stacktrace I use Spring for the transactionManager: org.springframework.orm.hibernate3.HibernateTransactionManager in which I use e sessionFactory: org.springframework.orm.hibernate3.LocalSessionFactoryBean
In my DAO, I try to save with the regular this.getHibernateTemplate().saveOrUpdate that has always worked for me.
Another problem I have:
when i update "name" in EDUCATION, the records with that ID are delete from EDUCATION_SCHOOLS ...
As I am experiencing 3 different problems, I'm pretty sure something is wrong in the mapping files .. however I fail to find out what .. Any input would be greatly appreciated.
(I translated some class/table-names, that's what the ## cause)
Edited by: Bart_Blommaerts on Jul 29, 2008 11:53 PM

Thank you for your input.
When I try what you suggest, I still get the same error:
16:39:30,406 [http-8081-1] ERROR ###.EpbExceptionHandler - org.springframework.orm.hibernate3.HibernateOptimisticLockingFailureException: Object of class [###.EducationSchools] with identifier [2]: optimistic locking failed; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [###.EducationSchools#2]
ex.getMessage() Object of class [###.EducationSchools] with identifier [2]: optimistic locking failed; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [###.EducationSchools#2]
org.springframework.orm.hibernate3.HibernateOptimisticLockingFailureException: Object of class [###.EducationSchools] with identifier [2]: optimistic locking failed; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [###.EducationSchools#2]
Caused by: org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [###.EducationSchools#2]If you had to map the database tables, I'm trying to map, how would you do it?

Many to Many Relationships in ejb.....Urgent Pls help

hi all,
Am working in EJB.Now we are coding for many to many relationship.
Company and Salary register
One Company can have many salary register and More than one company can have one salary register
Companyand Salary register are the two tables having details of it.And the intermediate table having pk of company and salary register is Company_salary_register table,I want to add the value in this table having seperate interface.
How to model it? I have given the add method of this company_salary_register table in company bean.I am getting the value of this one as collection.But it is asking me to add the values as the instance of LocalSalary(interfaceand entitybean).If i type cast it as Local Salary Class castexception occurs
Please help me.Even Material of Modelling Many to Many relationship in EJB is enough.
thanx in advance,

THaaaaaanks alottt for the quick reply...
I used the first way to insert the document and i was successful...
but thing is that..
when i do
SQL>desc message_type
message_type is NOT FINAL
Name Null? Type
SYS_XDBPD$ XDB.XDB$RAW_LIST_T
to VARCHAR2(4000 CHAR)
from VARCHAR2(4000 CHAR)
subject VARCHAR2(4000 CHAR)
body VARCHAR2(4000 CHAR)
i can see the structure...
and when i
select count(*) from messages
it says count is 1.
so how to know where the data is ..like below in the data :
'to' it has '[email protected]'
and for 'from' it has '[email protected]'..and so on..
<message>
<to>[email protected]</to>
<from>[email protected]</from>
<subject>Question</subject>
<body>Does this demo work?</body>
</message>
so what is the command to get that data...
because when i do
select * from message_type..it says
select * from message_type
ERROR at line 1:
ORA-04044: procedure, function, package, or type is not allowed here
Plss help me outt.......this will be my final step...
Thankssssssssssssssss

Creating data in a many-to-many-relationship

Hello,
we really have problems in implementing a JClient dialog based on BC4J for creating data in a many to many relationship - especially with cascade delete on both sides.
Simplified our tables look like:
create table A_TABLE
A_ID VARCHAR2(5) not null,
A_NAME VARCHAR2(30) not null,
constraint PK_A_TABLE primary key (A_ID),
constraint UK_A_TABLE unique (A_NAME)
create table B_TABLE
B_ID VARCHAR2(5) not null,
B_NAME VARCHAR2(30) not null,
constraint PK_B_TABLE primary key (B_ID),
constraint UK_B_TABLE unique (B_NAME)
create table AB_TABLE
A_ID VARCHAR2(5) not null,
B_ID VARCHAR2(5) not null,
constraint PK_AB_TABLE primary key (A_ID, B_ID),
constraint FK_AB_A foreign key (A_ID) references A_TABLE (A_ID) on delete cascade,
constraint FK_AB_B foreign key (B_ID) references B_TABLE (B_ID) on delete cascade
Could JDev Team please provide a BC4J/JClient sample that performs the following task:
The dialog should use A_TABLE as master and AB_TABLE as detail. The detail displays the names associated with the IDs. Next to AB_TABLE should be a view of B_TABLE which only displays rows that are currently not in AB_TABLE. Two buttons are used for adding and removing rows in AB_TABLE. After adding or removing rows in the intersection the B_TABLE view should be updated. The whole thing should work in the middle and client tier. This means no database round trips after each add/remove, no posts for AB_TABLE and no query reexecution for B_TABLE until commit/rollback.
This is a very common szenario: For an item group (A_TABLE) one can select and deselect items (AB_TABLE) from a list of available items (B_TABLE). Most of JDeveloper4s wizards use this. They can handle multi/single selections, selections from complex structures like trees and so on. Ok, the wizards are not based on BC4J - or? How can we do it with BC4J?
Our main problems are:
1. Updating the view of B_TABLE after add/remove reflecting the current selection
2. A good strategy for displaying the names instead of the IDs (subqueries or joining the three tables)
3. A JBO-27101 DeadEntityAccessException when removing an existing row from AB_TABLE and adding it again
Other problems:
4. We get a JBO-25030 InvalidOwnerException when creating a row in AB_TABLE. This is caused by the composition. We workaround this using createAndInitRow(AttributeList) on the view object (instead of create()). This is our add-Action:
ViewObject abVO = panelBinding.getApplicationModule().findViewObject("ABView");
ViewObject bVO = panelBinding.getApplicationModule().findViewObject("BView");
Row bRow = bVO.getCurrentRow();
NameValuePairs attribList = new NameValuePairs(
new String[]{"BId"}, new Object[]{bRow.getAttribute("BId")});
Row newRow = abVO.createAndInitRow(attribList);
abVO.insertRow(newRow);
5. After inserting the new row the NavigationBar has enabled commit/rollback buttons and AB_TABLE displays the row. But performing a commit does nothing. With the following statement after insertRow(newRow) the new row is created in the database:
newRow.setAttribute("BId", bRow.getAttribute("BId"));
Please give us some help on this subject.
Best regards
Michael Thal

<Another attempt to post a reply. >
Could JDev Team please provide a BC4J/JClient sample
that performs the following task:
The dialog should use A_TABLE as master and AB_TABLE
as detail. The detail displays the names associated
with the IDs. Next to AB_TABLE should be a view of
B_TABLE which only displays rows that are currently
not in AB_TABLE. Two buttons are used for adding and
removing rows in AB_TABLE. After adding or removing
rows in the intersection the B_TABLE view should be
updated. The whole thing should work in the middle
and client tier. This means no database round trips
after each add/remove, no posts for AB_TABLE and no
query reexecution for B_TABLE until commit/rollback.
This is a very common szenario: For an item group
(A_TABLE) one can select and deselect items
(AB_TABLE) from a list of available items (B_TABLE).
Most of JDeveloper4s wizards use this. They can
handle multi/single selections, selections from
complex structures like trees and so on. Ok, the
wizards are not based on BC4J - or? How can we do it
with BC4J?
Our main problems are:
1. Updating the view of B_TABLE after add/remove
reflecting the current selectionYou should be able to use insertRow() to insert the row into proper collection.
However to remove a row only from the collection, you need to add a method on the VO subclasses (and perhaps export this method so that the client side should see it) to unlink a row from a collection (but not remove the associated entities from the cache).
This new method should use ViewRowSetImpl.removeRowAt() method to remove the row entry at the given index from it's collection. Note that this is an absolute index and not a range index in the collection.
2. A good strategy for displaying the names instead
of the IDs (subqueries or joining the three tables)You should join the three tables by using reference (and perhaps readonly) entities.
3. A JBO-27101 DeadEntityAccessException when
removing an existing row from AB_TABLE and adding it
againThis is happening due to remove() method on the Row which is marking the row as removed. Attempts to add this row into another collection will throw a DeadEntityAccessException.
You may 'remove the row from it's collection, then call 'Row.refresh' on it to revert the entity back to undeleted state.
>
Other problems:
4. We get a JBO-25030 InvalidOwnerException when
creating a row in AB_TABLE. This is caused by the
composition. We workaround this using
createAndInitRow(AttributeList) on the view object
(instead of create()). This is our add-Action:
ViewObject abVO =
O =
panelBinding.getApplicationModule().findViewObject("AB
iew");
ViewObject bVO =
O =
panelBinding.getApplicationModule().findViewObject("BV
ew");
Row bRow = bVO.getCurrentRow();
NameValuePairs attribList = new NameValuePairs(
new String[]{"BId"}, new
String[]{"BId"}, new
Object[]{bRow.getAttribute("BId")});
Row newRow = abVO.createAndInitRow(attribList);
abVO.insertRow(newRow);This is a handy approach. Note that Bc4j framework does not support dual composition where the same detail can be owned by two or more masters. In those cases, you also need to implement post ordering to post the masters before the detail (and reverse ordering for deletes).
>
5. After inserting the new row the NavigationBar has
enabled commit/rollback buttons and AB_TABLE displays
the row. But performing a commit does nothing. With
the following statement after insertRow(newRow) the
new row is created in the database:
newRow.setAttribute("BId",
d", bRow.getAttribute("BId"));This bug in JDev 903 was fixed and a patch set (9.0.3.1) is (I believe) available now via MetaLink.
>
>
Please give us some help on this subject.
Best regards
Michael Thal

Many-to-many

We have several situations where we link tables with many-to-many relationships. We are having trouble modeling this with ODSI such that create, update, and delete operations work reliably. The problem is that the link table record needs to be created only after the related items are created, so that the primary keys exist before the foreign key record is inserted. On delete operations, the reverse is true: the link record must be deleted prior to the others, or foreign key constraints are violated. Can you please suggest a model that will accomodate this situation properly?
Thank you!
Jeff

I suspect the update cannot be done via a master->link->slave data service as ODSI has no way of knowing which which one of the slave records should be updated for a specific link. Does that make sense?
But your real problem is the referential integrity constraint. The last time I looked at many-to-many (ALDSP 2.x), I found that ds updates were executed in a deterministic order - which was determined by the iterator returned from HashMap (or something similarly unhelpful). And the solution was to write your own "update override" implementation. In ALDSP 3.x and ODSI 10.3 there is the update mapping and failing that you can write your own create/delete procedures. I know that is not terribly helpful, but that's all I have to offer without investigating.
- mike

Many-to-many mapping question

Hi,
I'm working with two classes Car and Customer. The Car class has a Vector of Customers and the Customer class has a Vector of Car. Both are related by a many to many mapping.
I have noticed that I have to set one of the vector to read only to avoid the error message "More than one writable many-to-many mapping can not use the same relation table" in the mapping workbench.
I can understand that but is there a way to work around, I mean to be able to add a car to a customer and add a customer to a car with the both vectors?
Is there something to do with the cache?
I use Vector for the collection or Map class, have I to do otherwise?

Hello Vladislav, I understand your first question in this thread, but I'm not sure I follow the rest, so let me respond to your first post:
"I have noticed that I have to set one of the vector to read only to avoid the error message "More than one writable many-to-many mapping can not use the same relation table" in the mapping workbench.
I can understand that but is there a way to work around, I mean to be able to add a car to a customer and add a customer to a car with the both vectors?"
The issue here is that with a Many to Many mapping the mapping is responsible for writing to the association table. So, you have a "CAR_CUST" association table. Imagine you add a Car "101" to a customer "501" and the requisite customer "501" to that car "101" in your object model. Then the association table should only be updated once, with an entry of "101, 501". But since the M-M is mapped in both directions, you need to tell TopLink which of these to consider as the "master" when updating the database.
If you didn't make one of the M-M mappings "read only", then TopLink would insert "101, 501" twice in the association table, and then at a later date you would see that the customer 501 had two 101 cars!
We do have a feature that allows for TopLink to maintain bidirectional relationships such that if you add or remove a target from one relationship, TopLink will automatically add/remove it from the opposite direction. In my opinion this is lazy programming! A good Java developer should insist on keeping his model up to date on his own. This feature was added because it's part of the EJB spec, not necessarily because it's a good idea ;)
- Don
Is there something to do with the cache?
I use Vector for the collection or Map class, have I to do otherwise?

ADF BC: Many-to-Many Insert

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