Serialization Graph and Self Referencing Objects or Circular Lists

Hello Everybody,
Let's say for instance you have a doubly linked circular list of some Object Obj in Java 6 and Obj implements Serializable.
What happens when the graph is it constructed and this circular list is Serialized?
Does the Serialization process build any sort of Direct Acyclic Graph possibly using some Topological Sort Algorithm?
Does it fail?
Or does it keep track of all the elements in the list that have already been serialized and ignores the elements that have been
already serialized following the references of the objects in the circular list?
Thanks in advance,
Carlos.

What happens when the graph is it constructed and this circular list is Serialized?It works. See the [Object Serialization Specification|http://java.sun.com/javase/6/docs/platform/serialization/spec/serial-arch.html].
Or does it keep track of all the elements in the list that have already been serialized and ignores the elements that have been
already serialized following the references of the objects in the circular list?It doesn't ignore them, it writes references to the already-written object instead of another copy. When deserializing, the references are resolved and the original object graph is restored correctly.

Similar Messages

JTree, BC4J and self referenced table

Hello.
table OBJECTS which has a primary key ID and a parent ref PARENTID.
This is to have a tree structure of objects.
I want that viewed in a JTree structure (using jclient and bc4j's)
How do i do that? if i do the obvious and use the object view with itself as accessor,
The tree is fine except ALL objects are stored on the rootlevel (of course).
Is there a way to make a polymorphic restriction only on root level, or do I use two viewobjects to represent the data? (and how would i do that the right way?)
Or is there another way?
Thanks.

Is there a way to make a polymorphic restriction only on root level, or do I use two viewobjects to represent the data? (and how would i do that the right way?)No you should not have to use Two different VOs. See a discussion on OTN thread:
Re: LDAP Authentication and DB user

Serialization in self-referencing classes

Okay, so I'm using Kodo 2.4.0, and I have a class Employee that has a List
property named 'managedEmployees':
private List managedEmployees = null;
The objects in this list are themselves of the class Employee. The JDO
configuration for it is:
<field name="fManagedEmployees" default-fetch-group="false">
<collection element-type="Employee" embedded-element="false"/>
<extension vendor-name="kodo" key="table" value="ps_employees"/>
<extension vendor-name="kodo" key="fEmployeeId-data-column"
value="emplid"/>
<extension vendor-name="kodo" key="fEmployeeId-ref-column"
value="manager_id"/>
</field>
When I serialize an object of this class it appears that Kodo is loading
the entire nested graph of Employees! Is there a configuration setting to
prevent this? Or need I create two different classes: Manager and
Employee, with managedEmployees as a property of Manager alone?

Self-referencing or not, JDO always recursively pulls in all relations during
serialization. If you do not want this to happen, make your object transient
(pm.makeTransient (obj)) before serializing it.

Object Serialization(Materialization and Dematerialization)

I've encountered some issues with mapping my objects to an RDBMS and am hoping for some advice.
I've tried various O/R mapping frameworks like Castor(too complex and too slow for my liking), JRF(nice but very repetitive and difficult to extend) and then some, but have yet to find one which I'm comfortable with building an application on.
Instead, I've chosen to do it the low-tech way, with each domain class, say Book for instance, having a Broker class which knows how to communicate with the chosen form of persistence. So, since I chose an RDBMS, Book class has a BookRelationalBroker class which knows how to materialize and dematerialize Book objects to and from a RDBMS. If so required, I can plug in a BookXMLBroker which knows how to serialize the object in the form of an xml data file.
I've also implemented a primitive object caching system which (when enabled), caches objects requested so we only have to materialize it from the db once.
Here are 2 issues I have with my system:
It is amazingly tedious (not to mention inefficient) to recreate the entire object from the database. This is even more so because I've implemented the Event Notification pattern, such that when say a book is deleted, the members who have reserved it are notified. The whole point of the Event Notification mechanism is so that the object being watched does not need to know of the objects which need to be notified on a state change. However, I've found it necessary to re-attach all the listeners on an object when it is materialized from the DB, defeating the purpose of the pattern.
Complex object relationships are mapped poorly and recursive materialization leads to slow response times. If a Group object has a Vector of Members and other Groups, then whenever a Group object is materialized, all its constituent Members and Group objects also need to be materialized. (I understand O/R frameworks solve this through lazy instantiation)
I studied the Jive2 architecture and found that they approached this problem by accessing the DB directly for any complex object relationships. In other words, the Group object does not actually contain a Vector of Members and Groups. Instead, it has a method called say getMembers() which proceeds to retrieve the necessary data from the DB and then materialize these objects.
I'm not too excited about this approach for 2 reasons:
How object-oriented is this approach? Seems more like database-oriented programming to me.
Every call to retrieve Members necessitates a call to the DB. The data isn't cached with the Group object because the Group object does not actually contain the necessary reference to the Members and Groups.
Can anyone shed some light on this topic?

How object-oriented is this approach? Seems more like database-oriented programming to me. There is a reason people still use Relational databases rather than OO DBs. First, is that the vast majority of data in the real world maps easily to a relational model, consequently there is no advantage to a OO model. Second, either because of this or simply because OO models are not computationally simple, OO databases tend to be slower than relational DBs.
It sounds like you are trying to implement a OO DB model using a relational database. So you basically end up with two problems. The DB is not optimized for OO models, and you have to find a way to map it in the OO model itself. And this is slow and messy.
To solve the slowness problem you could, just like EJB servers, cache the data in memory. Lot of work but if you want to do it then have fun.
The second way is to give up. Realize that your data model is not inherently OO'd and just implement it efficiently as a relational model. Then provide an interface that loads it into the OO model. And where needed add pass through logic to allow the database itself to do things it is really good at - like queries.

Self referencing table and SQL statement

In my database, I have a self-referencing table, the table itself is for projects, and it allows users to get a hierarchical view of the company.
Here is the SQL (modifier is the term we use for project code, BBCI is the top project)
SELECT
modifier, modifierDescription, level
FROM
modifier
WHERE
level <= 2
CONNECT BY PRIOR
modifier = parentModifier
START WITH modifier = 'BBCI'
ORDER BY level
That perticular query gets the first two levels in the structure. I use this information to produce a tree structure in a web app.
But users have requested it would be good if in the tree structure is showed an + or - depending on whether there were anymore children under each parent, or better still the number of children under it, for example
BBCI
+ BBCI_CHILD
+ BBCI_CHILD2
- BBCI_CHILD3
or
BBCI
+ BBCI_CHILD (3 projects underneath)
+ BBCI_CHILD2 (2 projects underneath)
- BBCI_CHILD3 (0 projects underneath)
I am really stumped on this issue, and I am sure there is a way to do this in the web app, so for example do a query for each child node to see how many child nodes are underneath, but I figure it would be a lot tidier and faster if I could do it from a single SQL statement. Unfortunately I have tried to do this and am very much stuck.
If you need more information please let me know
Thanks!
Jon

You may be able to do this using analytical functions but it depends on the Oracle version you are using. It can also be done with standard SQL - you just need to count the number of child rows for each modifier/project first and supply that list as an in-line view:
SELECT decode(modifier,'X',null,decode(child_rows,null,'-','+')),
m.modifier,
decode(modifier,'X',null,'('||nvl(cq.child_rows,0)||' projects underneath)')
FROM modifier m,
(select parentModifier,
count(parentModifier) child_rows
from modifier
where parentModifier is not null
group by parentModifier) cq
WHERE m.modifier=cq.parentModifier(+)
AND level <= 2
CONNECT BY PRIOR
m.modifier = m.parentModifier
START WITH modifier = 'X'
ORDER BY level, modifier;
which gives you something like...
D MODIFIER DECODE(MODIFIER,'X',NULL
X
- Y1 (0 projects underneath)
+ Y2 (2 projects underneath)
+ Y3 (3 projects underneath)
The decode stuff is just to show you the result, you can format the output in your calling code. Just extend the columns to include everything you want, modifierDescription etc..
Hope this helps.

Self referencing table and contraint

Hi,
I have a self referencing table, used to store information on projects in an organization. There is a pimary key (modifier) and a foreign key to the modifier field (parentModifier)
Note: (modifier = project in the organization)
Basically, the parentModifier cannot be equal to the modifier in the same table, or equal to any of its children, otehrwise you get wierd recursive relationships. Its like saying you cannot be your own father, or one of your children cannot be your father. To get a list of the modifiers the parentModifier cannot be, the following statement can be used:
select
modifier
from
modifier
where
modifier = 'A'
and
level >= 1
connect by prior
modifier = parentModifier
start with
modifier = 'A'
order by
level;
So, now, I guess the way to do this is perform that query in a trigger before each row is being updated, so the pseudo code would be something like:
BEFORE UPDATE ON modifier
FOR EACH ROW
DECLARE
modifierToChange varchar2(255);
modifierList ???;
BEGIN
select
modifier
into
modifierList
from
modifier
where
modifier = 'A'
and
level >= 1
connect by prior
modifier = parentModifier
start with
modifier = 'A'
order by
level;
if modifierToChange in modifierList
return error
else
execute query
end if
END
As you can see my PL/SQL is limitied. At the moment I can handle this at the application layer (in php), but if the admin going to SQL Plus and starts to fiddle, they can easy break the system, by setting an invalid relationship.
I was wondeirng, if anyone could give me some help or advice, it would be fantastic,
Thanks!

Having a unique key on mod_id would be enough to make sure the same element is not in the structure more than once. By allowing it to happed you will have all the descendants of the dup element following it when you walk the tree.
Let's say this is the intended behavior.
Consider the following test scenario:
create table modifier (
mod_id varchar2(10),
parent_mod_id varchar2(10)
insert into modifier (mod_id, parent_mod_id) values ('a', null);
insert into modifier (mod_id, parent_mod_id) values ('aa', 'a');
insert into modifier (mod_id, parent_mod_id) values ('ab', 'a');
insert into modifier (mod_id, parent_mod_id) values ('ac', 'a');
insert into modifier (mod_id, parent_mod_id) values ('aaa', 'aa');
insert into modifier (mod_id, parent_mod_id) values ('aab', 'aa');
insert into modifier (mod_id, parent_mod_id) values ('aac', 'aa');
insert into modifier (mod_id, parent_mod_id) values ('aba', 'ab');
insert into modifier (mod_id, parent_mod_id) values ('abb', 'ab');
insert into modifier (mod_id, parent_mod_id) values ('abc', 'ab');
insert into modifier (mod_id, parent_mod_id) values ('aca', 'ac');
insert into modifier (mod_id, parent_mod_id) values ('acb', 'ac');
insert into modifier (mod_id, parent_mod_id) values ('acc', 'ac');
insert into modifier (mod_id, parent_mod_id) values ('b', null);
insert into modifier (mod_id, parent_mod_id) values ('ba', 'b');
insert into modifier (mod_id, parent_mod_id) values ('bb', 'b');
insert into modifier (mod_id, parent_mod_id) values ('bc', 'b');
insert into modifier (mod_id, parent_mod_id) values ('baa', 'ba');
insert into modifier (mod_id, parent_mod_id) values ('bab', 'ba');
insert into modifier (mod_id, parent_mod_id) values ('bac', 'ba');
insert into modifier (mod_id, parent_mod_id) values ('bba', 'bb');
insert into modifier (mod_id, parent_mod_id) values ('bbb', 'bb');
insert into modifier (mod_id, parent_mod_id) values ('bbc', 'bb');
insert into modifier (mod_id, parent_mod_id) values ('bca', 'bc');
insert into modifier (mod_id, parent_mod_id) values ('bcb', 'bc');
insert into modifier (mod_id, parent_mod_id) values ('bcc', 'bc');
commit;
SQL> select lpad(' ', 2 * (level - 1)) || mod_id item
2    from modifier
3   start with parent_mod_id is null
4 connect by prior mod_id = parent_mod_id;
ITEM
a
aa
    aaa
    aab
    aac
ab
    aba
    abb
    abc
ac
    aca
    acb
    acc
b
ba
    baa
    bab
    bac
bb
    bba
    bbb
    bbc
bc
    bca
    bcb
    bcc
26 rows selected
Create a function to verify if a mod_id already is parent_mod_id's ascendant or descendant:
create or replace function exists_in_parents_branch
i_mod_id in varchar2
,i_parent_mod_id in varchar2
) return boolean is
pragma autonomous_transaction;
v_dummy varchar2(10);
begin
select mod_id
    into v_dummy
    from (select mod_id
            from modifier
           where mod_id = i_mod_id
          connect by prior mod_id = parent_mod_id
           start with mod_id = i_parent_mod_id
          union
          select mod_id
            from modifier
           where mod_id = i_mod_id
          connect by prior parent_mod_id = mod_id
           start with mod_id = i_parent_mod_id);
return true;
exception
when no_data_found then
    return false;
end exists_in_parents_branch;
Create a trigger that calls the function above for every insert and update
create or replace trigger biu_modifier
before insert or update on modifier
for each row
begin
if exists_in_parents_branch(:new.mod_id, :new.parent_mod_id) then
    raise_application_error(-20000, 'Cannot insert or update because of recursive relationship.');
end if;
end biu_modifier;
You are all set.
Here is a statement that should fail:
SQL> insert into modifier (mod_id, parent_mod_id) values ('bcc', 'b');
insert into modifier (mod_id, parent_mod_id) values ('bcc', 'b')
ERROR at line 1:
ORA-20000: Cannot insert or update because of recursive relationship.
ORA-06512: at "RC.BIU_MODIFIER", line 3
ORA-04088: error during execution of trigger 'RC.BIU_MODIFIER'
Here is a statement that should succeed:
SQL> insert into modifier (mod_id, parent_mod_id) values ('aaaa','aaa');
1 row created.

JPA: How to initialise an entity for a self-referencing table?

I am working on a project that requires a self-referencing table:
mysql> show create table attributes\G
*************************** 1. row ***************************
       Table: attributes
Create Table: CREATE TABLE `attributes` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`parent` int(11) DEFAULT NULL,
`type` int(11) DEFAULT NULL,
`name` varchar(128) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `parent` (`parent`),
KEY `type` (`type`),
CONSTRAINT `attributes_ibfk_1` FOREIGN KEY (`parent`) REFERENCES `attributes` (`id`),
CONSTRAINT `attributes_ibfk_2` FOREIGN KEY (`type`) REFERENCES `attributes` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=26 DEFAULT CHARSET=latin1
I used NetBeans to generate an entity class from the table:
@Entity
@Table(name = "attributes")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "Attributes.findAll", query = "SELECT a FROM Attributes a"),
    @NamedQuery(name = "Attributes.findById", query = "SELECT a FROM Attributes a WHERE a.id = :id"),
    @NamedQuery(name = "Attributes.findByName", query = "SELECT a FROM Attributes a WHERE a.name = :name")})
public class Attributes implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "id")
    private Integer id;
    @Size(max = 128)
    @Column(name = "name")
    private String name;
    @OneToMany(mappedBy = "parent")
    private Collection<Attributes> attributesCollection;
    @JoinColumn(name = "parent", referencedColumnName = "id")
    @ManyToOne
    private Attributes parent;
    @OneToMany(mappedBy = "type")
    private Collection<Attributes> attributesCollection1;
    @JoinColumn(name = "type", referencedColumnName = "id")
    @ManyToOne
    private Attributes type;
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "attributes")
    private Collection<ItemAttributes> itemAttributesCollection;
    @OneToMany(mappedBy = "ivalue")
    private Collection<ItemAttributes> itemAttributesCollection1;
But how can I write a constructor for this entity? The auto-generated code gets around the issue by doing nothing; the constructor is empty. I can't help thinking that if I set the parent and type references to anything with new Attributes(), then it will recurse out of control. What else can/shall I do? I know how to rewrite it to not use the entity relations, but I'd prefer to make it work.

Cymae wrote:
I don't want to call the hash table creation method because from what i understand about interfaces the idea is that your main method doesnt know the table is actually a hash table...is that right?That's not exactly the idea. The idea to use the interface as the type instead of the implementation, is that your class probably doesn't need to know the full type. This makes it easy to change the implementation of the interface if needed. However, somebody at some point has to create the concrete object, a HashTable.
Basically, an interface describes a behavior, and a class that implements an interface decides how to actually perform this behavior. It is obviously impossible to perform the behavior if you are not told how to perform it.
Table table = new HashTable() is the correct way to do it. This means that if you ever need you Table implementation to change, the only thing you need to change in your whole class is this line. For example you might want Table table = new FileTable().

Need help on self referencing a ssrs report

Hi All,
I have a graph on one of my report which shows data on level 1 by default and go on showing level 2 and level 3 data on successive clicks. This has been achieved by self referencing a ssrs report and passing respective parameters. Now to identify which level
data needs to be shown on graph, I have used one more parameter which default value is 1 and go on increasing to 2 then 3 on successive click and this parameter value is used in group expression of graph. This works just fine.
But the real problem has occurred when you go and select report parameters which are corresponding to level 1, level 2 and level 2 values and click on apply in between. For e.g. Assume level 1=Region, level 2=SubRegion and level 3=Country. When you run this
report it shows region wise data on graph and value of fourth parameter is 1, now when you click on graph it takes you to level 2 i.e. it shows sub region wise data on graph and value of fourth parameter is 2 but when you go and select all region, sub region
and countries from report parameters and click on apply button then it should show data on graph region wise but since the time you were selecting parameter data was sub region wise and value of fourth parameter was 2 it shows data for all sub regions which
is weird and not acceptable at all.
I am hoping SSRS should provide a way to pass parameters just like we pass in action on any control within ssrs report to solve this issue. Please help me out to solve this issue or let me know if need more infor.

Hi,
There was an error reading from the pipe: Unrecognized error 109 (0x6d).
One reason was inconsistent binding between client and server <netNamedPipeBinding> <security mode="None"></security>... (no
communication)
The other intermittent issue was time-out related.
For more information, you could refer to:
http://stackoverflow.com/questions/15836199/wcf-namedpipe-communicationexception-the-pipe-has-been-ended-109-0x6d
http://stackoverflow.com/questions/22334514/wcf-named-pipe-error-the-pipe-has-been-ended-109-0x6d
Regards

Problem with self referencing cells

Hello there,
I'd like to have two columns that are NULL, unless the other column has a value entered into it.
This seems to create an infinite lookup loop of self referencing.
Can anyone suggest a work around?
Please see example
http://public.iwork.com/document/?a=p175104233&d=self_reference.numbers

If for instance you have
cell B2 = IF(C2="","","Not Null")
and
cell C2 = IF(B2="","", "Not Null")
then, yes, you have a circular reference
It sounds like what you want is if you enter (by hand, overwriting the formula that is there) a value in B2 then the formula in C2 will result in a value (not null). If you, instead, enter a value in C2 then the formula in B2 will result in a value.
Try this addition to the formula:
B2=IFERROR(IF(C2="","","not null"),"")
C2=IFERROR(IF(B2="","","not null"),"")
In other words, wrap it all up in an IFERROR
Message was edited by: Badunit

EJB-QL with self referencing cmr-field in path identifier fails

I have a simple application . Only one bean and one relationship. The relationship is a (0..1)-(0..1) for the same bean (self referencing).
I have a finder method defined with ejb-ql that tries to access the field of one of the cmr fields of the relationship.
class1Bean is the abstract schema for my bean, and subclass1 is the cmr-field name.
SELECT OBJECT(obj) FROM class1Bean obj WHERE obj.subclass1.id LIKE ?1
Here is the error message when trying to deploy:
Bean: Class1
Method: java.util.Collection findBySubclass1(java.lang.String)
EJBQL: SELECT OBJECT(obj) FROM class1Bean obj WHERE obj.subclass1.id LIKE ?1
Error: JDO75100: Fatal internal error: JDO75341: Missing field meta data for field 'subclass1' of 'Class1'
This same code deploys fine on JBoss 4.0, and should be legal ejb-ql. Is this a known issue with Sun JSAS?

Sounds like a problem with the bean metadata. Please check the entity mapping defined in sun-cmp-mappings.xml. Also make sure field sublass1 is defined as CMR everywhere.
-- markus.

Self Referencing Tables...

I have a self-referencing table (a Topic can be a response to another Topic) and read one of Frank Nimphius' blogs on this subject, posted on the ADF board for advise. As a result I created the read-only ViewObject to set up this tree relationship and set it to be exposed to the App Module.
Do I need to do more to it than that for JHeadstart to generate the right page defs? Any advise on setting this up cleanly? My user interface must present a page in which users can post new Topics, view topics in a heirarchy (response thread, like in this forum) and respond to Topics or responses. A response is a Topic that references another (parent) Topic. I have to believe this has been done before a million times but am not sure myself how to do it.
Thanks!

Steve,
I've read the section and am getting this error:
(oracle.jbo.SQLStmtException) JBO-27122: SQL error during statement preparation. Statement: SELECT Topic.SUBJECT, Topic.ROW_ID, Status.STATUS_CHOICE, Status.ROW_ID AS ROW_ID11, Topic.CREATED_BY, Topic.CREATION_DATE, Response.SUBJECT AS SUBJECT1, Response.CREATION_DATE AS CREATION_DATE1, Response.ROW_ID AS ROW_ID12, Response.CREATED_BY AS CREATED_BY1 FROM TOPIC Topic, RESPONSE Response, STATUS Status WHERE (Topic.ROW_ID = Response.MASTER_ID (+)) AND (Topic.TOPIC_STATUS_ID = Status.ROW_ID) CONNECT BY PRIOR Topic.ROW_ID = Response.MASTER_ID (+) OR Response.ROW_ID = Response.MASTER_ID (+) ORDER BY SUBJECT,CREATION_DATE1
----- LEVEL 1: DETAIL 0 -----
(java.sql.SQLException) ORA-01436: CONNECT BY loop in user data
I have a table called Topic with a Pk called ROW_ID and another table called Response with a Pk called ROW_ID and an Fk called MASTER_ID. A Topic can have many Responses and a Response can also have many Responses. The parent ID could point to either a Topic or a Response. There's no limit on how many levels this can continue. There's a Status table also from which I want to show the text value of the Status for the Topic row (not the Status ROW_ID)
I have a View Object including entities: Topic, Response & Status
I tried the SQL query as:
(Topic.ROW_ID = Response.MASTER_ID (+)) AND (Topic.TOPIC_STATUS_ID = Status.ROW_ID) CONNECT BY PRIOR Topic.ROW_ID = Response.MASTER_ID (+) OR Response.ROW_ID = Response.MASTER_ID (+)
Hoping to have this result:
Topic A
-Response A (to Topic A)
--Response B (to A)
---Response C (to B)
-Response D (to Topic A)
Topic B
Topic C
What am I doing wrong?
Is there a guide that explains better using JHeadstart with JDeveloper (rather than Oracle Designer, which we don't use)? The developer's guide for JHeadstart is hard to translate for use with JDeveloper...
Thanks!!

Searchnig self-referencing HierarchyViewer ?

Any example how to search self-referencing View object using dvt:search & dvt:searchResult ?
The applied ViewCriteria for root nodes is :
MASTER_ID IS NULL

Steve,
I've read the section and am getting this error:
(oracle.jbo.SQLStmtException) JBO-27122: SQL error during statement preparation. Statement: SELECT Topic.SUBJECT, Topic.ROW_ID, Status.STATUS_CHOICE, Status.ROW_ID AS ROW_ID11, Topic.CREATED_BY, Topic.CREATION_DATE, Response.SUBJECT AS SUBJECT1, Response.CREATION_DATE AS CREATION_DATE1, Response.ROW_ID AS ROW_ID12, Response.CREATED_BY AS CREATED_BY1 FROM TOPIC Topic, RESPONSE Response, STATUS Status WHERE (Topic.ROW_ID = Response.MASTER_ID (+)) AND (Topic.TOPIC_STATUS_ID = Status.ROW_ID) CONNECT BY PRIOR Topic.ROW_ID = Response.MASTER_ID (+) OR Response.ROW_ID = Response.MASTER_ID (+) ORDER BY SUBJECT,CREATION_DATE1
----- LEVEL 1: DETAIL 0 -----
(java.sql.SQLException) ORA-01436: CONNECT BY loop in user data
I have a table called Topic with a Pk called ROW_ID and another table called Response with a Pk called ROW_ID and an Fk called MASTER_ID. A Topic can have many Responses and a Response can also have many Responses. The parent ID could point to either a Topic or a Response. There's no limit on how many levels this can continue. There's a Status table also from which I want to show the text value of the Status for the Topic row (not the Status ROW_ID)
I have a View Object including entities: Topic, Response & Status
I tried the SQL query as:
(Topic.ROW_ID = Response.MASTER_ID (+)) AND (Topic.TOPIC_STATUS_ID = Status.ROW_ID) CONNECT BY PRIOR Topic.ROW_ID = Response.MASTER_ID (+) OR Response.ROW_ID = Response.MASTER_ID (+)
Hoping to have this result:
Topic A
-Response A (to Topic A)
--Response B (to A)
---Response C (to B)
-Response D (to Topic A)
Topic B
Topic C
What am I doing wrong?
Is there a guide that explains better using JHeadstart with JDeveloper (rather than Oracle Designer, which we don't use)? The developer's guide for JHeadstart is hard to translate for use with JDeveloper...
Thanks!!

Synchronize form with self-referencing VO in tree table. POJO Based Model

Hello. I need your help
ADF Code Corner sample #32 show how to build a tree table from a self referencing VO:
[http://www.oracle.com/technetwork/developer-tools/adf/learnmore/index-101235.html#CodeCornerSamples]
ADF Code Corner document Oracle JDeveloper OTN Harvest 09/2011 by Frank Nimphius show how to build an edit form for the table data and how to synchronize it with the selected row in the tree table:
[http://www.oracle.com/technetwork/developer-tools/adf/learnmore/sept2011-otn-harvest-508189.pdf]
This examples are helpful, but i have a problem, i have not a model based on a database, my application datamodel is based in POJO objects, there are no appModules or ViewObjects so I do not know how to reference the tree table target attribute with the edit form iterator.
Can anyone help me?
Maybe (i dont know how) i need make a VO and a AppModule that wraps the POJO model ?
thank you very much

Hi,
this should work the same. You create a tree from a POJO Data Control based on your POJO Model. Expose another collection pointing to the same data set and drag it as the form. Use the setting on the tree configuration dialog to set the current row in the tree as the current in the form iterator.
Frank

How to find out the Referenced objects ?

Hi all,
I want to find out the referenced objects
Example : Table Name is Customer
I want to know what are the procedures,functions,packages used that customer table. Please provide that sql Query.
Thanks and Regards

If this is not what you want, please give us a test case with input and expected output:
SQL>
SQL> drop table cust;
Table dropped.
SQL> drop procedure proc1;
Procedure dropped.
SQL> drop procedure proc2;
Procedure dropped.
SQL> drop procedure proc3;
Procedure dropped.
SQL>
SQL> create table cust(x int);
Table created.
SQL>
SQL> create procedure proc1
2 is
3 begin
4 update cust set x = x + 1;
5 end;
6 /
Procedure created.
SQL> show errors
No errors.
SQL>
SQL> create procedure proc2
2 is
3 begin
4 delete cust;
5 end;
6 /
Procedure created.
SQL> show errors
No errors.
SQL>
SQL> create procedure proc3
2 is
3 begin
4 insert into cust values(0);
5 end;
6 /
Procedure created.
SQL> show errors
No errors.
SQL>
SQL> select name, type
2 from all_dependencies
3 where
4 type ='PROCEDURE'
5 and referenced_name = 'CUST'
6 and referenced_type = 'TABLE';
NAME                           TYPE
PROC1                          PROCEDURE
PROC2                          PROCEDURE
PROC3                          PROCEDURE
SQL> exit

Best practice: self referencing table

Hallo,
I want to load a self referencing table to my enterprise area in the dwh. I am not sure how to do this. What if a record references to another record which is inserted later in the same etl process? There is now way to sort, because it is possible that record a references to record b and record b references to record a. Disabling the fk constraint is not a good idea, because this doesn't prevent that invalid references will be loaded? I am thinking of building two mappings, one without the self referencing column and the other only with it, but that would cause approx. twice as much running time. Any other solutions?
Regards,
Torsten

Mind sharing the solution? Would be interested to hear your solution (high level).
Jean-Pierre

Serialization Graph and Self Referencing Objects or Circular Lists

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