Additional properties on Many-to-Many relation

Hi,
I've trawled through the archive and can't see if this is answered (nor can I find it in the documentation) so apologies if I've missed something obvious.
I have a logical model with several many-to-many relationships. Clearly I can (and probably should) resolve them, but for a number of reasons I'd prefer, for now, to leave them as m:n.
On at least one of the m:n I want to add additional (non-FK attributes) to the relationship. There is even a section of the Relation Properties dialog that looks like it should allow me to do so (Attributes) but this is only populated in a 1:m relationship.
Is there any way of directly adding the non-FK attributes to the relationship? Or do I have to resolve the m:n and add the attributes to the new entity? Or is there some way in the transformation of adding the attributes?
Thanks
Ian

Hi Ian,
I want to add additional (non-FK attributes) to the relationshipIt's not possible in current release.
It's better to resolve the relationship to entity and to add attributes there.
Philip

Similar Messages

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

Problem in mapping a many to many relation to a list

Hi,
I have a problem with mapping a many to many relation to a list.
I have a Many to Many relation in my database between tables baskets and products. This relation is implemented with a join table basket_products, which has two fields which correspond to the foreign keys to tables baskets and products. The join table need to have another one column "order", which defines the order of the products for the specific basket.
In my mapping I have:
@Entity
@Table(name = "baskets", uniqueConstraints = {})
public class Components implements java.io.Serializable {
@ManyToMany(cascade = { CascadeType.ALL }, fetch = FetchType.LAZY)
     @JoinTable( name="baskets_products",
                         joinColumns=@JoinColumn(name="b_id", referencedColumnName="pr_id"),
                         inverseJoinColumns=@JoinColumn(name="pr_id", referencedColumnName="pr_id"))
        //This of course doesn't work!!
       //@OrderBy(value="order")
     public List<Products> getProductses() {
          return this.productses;
     public void setProductses(
               List<Products> productses) {
          this.productses = productses;
@Entity
@Table(name = "products", uniqueConstraints = { })
public class Products implements java.io.Serializable {
@ManyToMany(cascade = { CascadeType.ALL }, fetch = FetchType.LAZY, mappedBy = "productses")
     public Set<Baskets> getBasketses() {
          return this.basketses;
     public void setBasketses(Set<Basket> basketses) {
          this.basketses = basketses;
     }In the EJB spec I read that :
"The property or field name must correspond to that of a persistent property or field of the associated
class."
What to do if I want to use a field from the join table to do the ordering of the list??
My problem is that the field "order", is not defined to the EJB container as a persistent field, so it cannot be used. But for my needs it is necessary that this field is included in the join table.
I thought that I could use the secondary table annotation to map the join table to the Baskets class, as well, so that I can define the order field, but this solution seems to me as a really wrong one.
Can anyone help me??
Thanks,
Elenh.

Hi Martin-
Can you please help me. Here are the details:
We have created an AQ in Oracle DB which will have the following message Structure:
CREATE OR REPLACE TYPE enqueue_payload AS OBJECT
( field1 VARCHAR2(100),
field2 VARCHAR2(100),
field3 DATE,
field4 VARCHAR2(100),
field5 NUMBER,
payload CLOB,
In the Payload field we are enqueing an XML message.
We have to use a OSB proxy service to dequeue the message from the AQ, transform it to another format and send to a SOA Composite.
We created a AQ Adapter in Jdeveloper 11g and imported the WSDL, XSD and .jca jca binding file into the OSB project. And configured the OSB proxy service using the WSDL imported.
However in OSB proxy service message flow when I try to create an XQUERY transformation, I see that the Payload field does not expose the structure of the XML message that is being enqueued. I even changed the message structure definition to have the payload field as XMLType. But it didn't help.
On analyzing the XSD created by AQ Adapter, I see that the payload is being defined as "string" in the XSD.
Inputs Needed
=========
1. How can we parse the payload field defined as CLOB/XMLType in OSB so that I can see the structure of the XML message it holds ?
2. Is there any in-built function in OSB to convert it to XML ?
3. Any other inputs in order to transform the XML message coming in the payload field as CLOB/XMLType
Please provide your inputs and I hope that I have clearly explained my use case.
Thanks in advance for your time and help!!
Regards,
Dibya

Many-to-many relation

Hi,
There is a many-to-many relation defined for the following tables:
Table T_PRICEAFFECTOR
Name Type
NAME VARCHAR2(100)
ISACCUMULATIVE NUMBER(1)
RATE NUMBER(10,10)
PRICEAFFECTOR_ID NOT NULL NUMBER(10)
CATALOG_ID NOT NULL NUMBER(10)
UNITTYPE NOT NULL NUMBER(1)
and
Table T_PRICEAFFECTINGCHAIN
Name Type
PRICEAFFECTINGCHAIN_ID NOT NULL NUMBER(10)
NAME VARCHAR2(100)
ISDEFAULTFORSTORE NUMBER(1)
CATALOG_ID NOT NULL NUMBER(10)
There is also a third table defining the many-to-many relation:
TABLE T_PRICEAFFECTORTOCHAIN
Name Type
PRICEAFFECTOR_ID NOT NULL NUMBER(10)
PRICEAFFECTINGCHAIN_ID NOT NULL NUMBER(10).
The classes defined are as follows:
public class PriceAffectorsChain
     private Catalog catalog;
     private long priceAffectorsChainId;
     private String name;
     private boolean isDefaultForStore;
     private Collection priceAffectors = new HashSet ();
     private Collection products = new HashSet ();
public class PriceAffector
     private long priceAffectorId;
     private long isAccumulative;
     private String name;
     private double rate;
     private Catalog catalog;
     private int unitType;
     private Collection priceAffectorsChains = new HashSet ();
and these are defined in the jdo descriptor in the following way:
<class name="PriceAffector" identity-type="application"
objectid-class="jp.telewave.platpark.eis.dao.pk.PriceAffectorPK">
     <extension vendor-name="kodo" key="lock-column" value="none"/>
     <extension vendor-name="kodo" key="class-column" value="none"/>
     <extension vendor-name="kodo" key="table" value="T_PRICEAFFECTOR"/>
     <field name="priceAffectorId" primary-key="true">
          <extension vendor-name="kodo" key="data-column"
value="PRICEAFFECTOR_ID"/>
     </field>
     <field name="isAccumulative">
          <extension vendor-name="kodo" key="data-column" value="ISACCUMULATIVE"/>
     </field>
     <field name="name">
          <extension vendor-name="kodo" key="data-column" value="NAME"/>
     </field>
     <field name="rate">
          <extension vendor-name="kodo" key="data-column" value="RATE"/>
     </field>
     <field name="unitType">
          <extension vendor-name="kodo" key="data-column" value="UNITTYPE"/>
     </field>
     <field name="catalog">
          <extension vendor-name="kodo" key="catalogId-data-column"
value="CATALOG_ID"/>
     </field>
     <field name="priceAffectorsChains">
          <collection element-type="PriceAffectorsChain"/>
          <extension vendor-name="kodo" key="read-only" value="true"/>
          <extension vendor-name="kodo" key="inverse" value="priceAffectors"/>
          <extension vendor-name="kodo" key="table"
value="T_PRICEAFFECTORTOCHAIN"/>
          <extension vendor-name="kodo" key="priceAffectorId-ref-column"
value="PRICEAFFECTOR_ID"/>
          <extension vendor-name="kodo" key="priceAffectorsChainId-data-column"
value="PRICEAFFECTINGCHAIN_ID"/>
     </field>
</class>
<class name="PriceAffectorsChain" identity-type="application"
objectid-class="jp.telewave.platpark.eis.dao.pk.PriceAffectorsChainPK">
     <extension vendor-name="kodo" key="lock-column" value="none"/>
     <extension vendor-name="kodo" key="class-column" value="none"/>
     <extension vendor-name="kodo" key="table" value="T_PRICEAFFECTINGCHAIN"/>
     <field name="priceAffectorsChainId" primary-key="true">
          <extension vendor-name="kodo" key="data-column"
value="PRICEAFFECTINGCHAIN_ID"/>
     </field>
<field name="catalog">
          <extension vendor-name="kodo" key="catalogId-data-column"
value="CATALOG_ID"/>
     </field>
     <field name="name">
          <extension vendor-name="kodo" key="data-column" value="NAME"/>
     </field>
     <field name="isDefaultForStore">
     <extension vendor-name="kodo" key="data-column"
value="ISDEFAULTFORSTORE"/>
     </field>
     <field name="priceAffectors">
          <collection element-type="PriceAffector"/>
          <extension vendor-name="kodo" key="read-only" value="false"/>
          <extension vendor-name="kodo" key="inverse"
value="priceAffectorsChains"/>
          <extension vendor-name="kodo" key="table"
value="T_PRICEAFFECTORTOCHAIN"/>
          <extension vendor-name="kodo" key="priceAffectorsChainId-ref-column"
value="PRICEAFFECTINGCHAIN_ID"/>
          <extension vendor-name="kodo" key="priceAffectorId-data-column"
value="PRICEAFFECTOR_ID"/>
     </field>
     <field name="products">
     <collection element-type="Product"/>
     <extension vendor-name="kodo" key="inverse" value="priceAffectorsChain"/>
     </field>
</class>
=============================================================
Ok. The problem with the mapping is that it works only one way. What I
mean is that when I try to add new PriceAffectorsChain with many
PriceAffector objects only the PriceAffectorsChain object is being
persisted, and none of the PriceAffectors are persisted in the
many-to-many table (T_PRICEAFFECTORTOCHAIN), even when the read-only
extensions are set.
That was not the case when I tried to add new PriceAffector with many
PriceAfffectorsChain - everything worked.
Any Ideas?
-Ivan

Abe White wrote:
When you have a two-sided relation, you need to be maintaining both sides
of the relation at all times. Whenever an A is added to a B, the B must
be added to the A as well. Keep your in-memory Java objects consistent
(just as if they were not persistent), and JDO will take care of the rest.Abe White wrote:
When you have a two-sided relation, you need to be maintaining both sides
of the relation at all times.
Whenever an A is added to a B, the B must
be added to the A as well. Keep your in-memory Java objects consistent
(just as if they were not persistent), and JDO will take care of the rest.Ok. I agree.
I think that I'm doing this or maybe I'm wrong. Below is the code that
adds new price affectors chain with collection of price affectors (all of
them already persistent). Each of the price affectors is being looked up
and is consistent (this is what getObjectById is doing, isn't it?) and
then the price affector chain is being persisted.
=================================================================
PersistenceManager pm = null;
PriceAffectingChain newPriceAffectorsChain = null;
HashSet priceAffectors = null;
try {
pm = persistenceManagerFactory.getPersistenceManager();
// getting the catalog object
long catalogId = priceAffectorsChain.getCatalog().getCatalogId();
CatalogPK catalogPK = new CatalogPK(catalogId);
Catalog newPriceAffectorsChainCatalog =
(Catalog)pm.getObjectById(catalogPK, true);
// making new price affecting chain
newPriceAffectorsChain = new PriceAffectingChain(
BeanHelper.getNextSequence(DBObjects.SEQ_PRICEAFFECTINGCHAIN),
priceAffectorsChain.getName(),
     priceAffectorsChain.getIsDefaultForStore(),
     newPriceAffectorsChainCatalog);
// retrieval of price affector objects for this chain
System.out.println("the size of the price affectors is: " +
priceAffectorPKs.length);
if (priceAffectorPKs != null && priceAffectorPKs.length > 0) {
     priceAffectors = new HashSet(priceAffectorPKs.length);
for (int i = 0; i < priceAffectorPKs.length; i++) {
          PriceAffectorPK currentPAPK = priceAffectorPKs;
          PriceAffector currentPA = (PriceAffector)pm.getObjectById(currentPAPK,
true);
          priceAffectors.add(currentPA);
          System.out.println("The " + currentPA.getName() + " price affector was
added");
if (priceAffectors == null) {
     priceAffectors = new HashSet();
System.out.println("size of priceAffectors: " +
priceAffectors.size());
newPriceAffectorsChain.setPriceAffectors(priceAffectors);
pm.makePersistent(newPriceAffectorsChain);
} catch {
===========================================================
The problem is that the presistence works only for the table of
PriceAffectingChain obejct and not for the relation table. I tried on
purpose to add new price affectors with collection of price affecting
chains and it worked for both tables (the one for PriceAffector object and
the relation table.
I have no idea what I can try next. Any advice or help are welcomed.
Thanks.
-Ivan

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SQLIntegrityConstraintViolationException in a "many to many" related tables

Hi, in an 11g adf application I have a “many to many” relationship between two tables A and B and an intermediate table C that relates them.
The database has constraints that check for id existence in master tables before saving rows in C.
When I’m trying to create a new entry in B’s UI form with relations to A I’m getting a:
java.sql.SQLIntegrityConstraintViolationException: ORA-02291:
the framework seems that tries to save the row in C before B. So there doesn’t exist the id in B.
The same operation in A table’s UI form is executed properly. The framework first creates a row in A
and then related it with B creating rows in C and no constraint violation is thrown.
Why is this happening?
Any comment will be helpful.
Thanks

Using BC Tester the save operation is executed properly without errors.
The constraint you are asking is a classic referential constraint in intermediate table C that requires when creating new rows in C the foreign key refer to B to pre-exist in B table.
So the sequence of save operation is important when creating new rows in B and C table.
If I create a new row in B, save it and then create relations as new rows in C everything is fine.
But if I concurrently create a new row in B with rows in C, the framework seems that tries to save firstly the rows in C and then in master table B so the referential integrity is violated.
Is it possible in ADF to influence to order of saves in master detail tables and how is this specified?
For example the same operation with same integrity constraints in UI form of A table is executed properly.

Many to Many relation problem

Hi,
JDeveloper 11.1.1.6
3 tables, let's name them A, B and RelAB
By default, there is a [1 to *] from A to RelAB and a [1 to *] from B to RelAB.
Since I wanted to use a master-detail view on my web page, I didn't have the choice to modify these Associations and Links to a [* to *] from A to B, and as well from B to A.
Now you test the whole thing by running the AppModule. Everything works like a charm.
The problem is if I go into my A view object and then I change the SQL Mode from Normal to Expert inside the Query tab, the minute I run my AppModule, one of my many to many relationship breaks. Notice that I did not change anything else, just switch from Normal to Expert. Let's say that the A to B relation is working but not the B to A.
If I put it back to Normal, it works again. You might want to ask, why bother with Expert Mode? It is just that I want to modify this query, I was just trying to identify the source of the problem.
Anybody experience a similar problem with many-to-many relationships?

I assume your question is on JAXB, correct?
I think you need to make on side of the relationship transient, or remove it.
James : http://www.eclipselink.org

What is the best way to implement writable many-to-many relations

As everyone knows, the many-to-many associations provided by BC4J are quite good to read many-to-many associations, but they are not able to write such associations.
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I'd appreciate any hint
Thanks

A many-to-many relational problem (SQL and CFM)

My question:
How to get CFM to return a many-to-many relationship in one
row using cfloop
My table structure:
Table A - Books
BookID | BookName
1 | Book One
Table B -
RelatingTable
BookID | AuthorID
1 | 60
1 | 61
Table C - Authors
AuthorID | AuthorName
60 | Bob
61 | Joe
My query:
SELECT * FROM Books, RelatingTable, Authors AS a
INNER JOIN Books AS b ON b.BookID = r.BookID
INNER JOIN RelatedTable AS r ON r.AuthorID = a.AuthorID
Output I am getting:
b.BookID | b.BookName | r.BookID | r.AuthorID | a.AuthorID |
a.AuthorName
---------|------------|----------|------------|------------|-------------
1 | Book One | 1 | 60 | 60 | Bob
1 | Book One | 1 | 61 | 61 | Joe
I am using a UDF that turns my relationship into a comma list
(authorlist), but the duplicates still return in CFM because the
JOIN relationship
The code I am using in CFM:
<cfloop query="rsBooksQuery">
#b.BookName#, written by #authorlist#
</cfloop>
How Coldfusion is displaying my output:
Book One, written by Bob, Joe
Book One, written by Bob, Joe
How I want my output displayed:
Book One, written by Bob, Joe
I need this to work in cfloop and not cfoutput! I know that
you can use group in CF output, but for the conditions I am using
this query, it must be in a loop
the reason why i keep the JOINs even though i have a UDF to
create a comma list is that some of my CFM pages use variables
passed to the qry to limit which books are displayed, for example
&author=60 (which would display a list of Bob's books that
include the comma list)
If you can suggest anything to help me I will be very
thankful

I need this to work in cfloop and not cfoutput! I know that
you can use
group in CF output, but for the conditions I am using this
query, it
must be in a loop
If you can suggest anything to help me I will be very
thankful
If you can not use <cfoutput...> with its group
feature, you need to
recreate the functionality with <cfloop...>. You can
create nested
<cfloop...> tags that keep track of the changing group
value. It takes
more code, but that's what happens when one sets outside the
bounds of
the built in functionality.

Many to Many Relations Problem

I have following two classes with many-to-many case:
public class Protocol {
private long protocolId;
private final Collection keyPersons = new ArrayList();
public void addKeyPerson(Person person) {
person.addKeyProtocol(this);
public void removeKeyPerson(Person person) {
person.removeKeyProtocol(this);
public class Person {
private long personId;
private final Collection keyProtocols = new ArrayList();
public void addKeyProtocol(Protocol protocol) {
protocol.getKeyPersonsCollection().add(this);
keyProtocols.add(protocol);
public void removeKeyProtocol(Protocol protocol) {
protocol.getKeyPersonsCollection().remove(this);
keyProtocols.remove(protocol);
The meta data is:
<?xml version="1.0"?>
<jdo>
<package name="peacetech.nih.nhlbi.iasp.dao">
<class name="Protocol" identity-type="application"
objectid-class="peacetech.nih.nhlbi.iasp.dao.oid.ProtocolOid">
<extension vendor-name="tt" key="table" value="protocol"/>
<extension vendor-name="tt" key="pk-column" value="int_protocol"/>
<extension vendor-name="tt" key="lock-column" value="none"/>
<extension vendor-name="tt" key="class-column" value="none"/>
<field name="protocolId" primary-key="true">
<extension vendor-name="tt" key="data-column" value="int_protocol"/>
</field>
<field name="keyPersons">
<collection element-type="Person"/>
<extension vendor-name="tt" key="inverse" value="keyProtocols"/>
<extension vendor-name="tt" key="table" value="KeyPersonnel"/>
<extension vendor-name="tt" key="personId-data-column" value="PID"/>
<extension vendor-name="tt" key="protocolId-ref-column"
value="int_protocol"/>
</field>
</class>
<class name="Person" identity-type="application"
objectid-class="peacetech.nih.nhlbi.iasp.dao.oid.PersonOid">
<extension vendor-name="tt" key="table" value="Personnel"/>
<extension vendor-name="tt" key="pk-column" value="PID"/>
<extension vendor-name="tt" key="lock-column" value="none"/>
<extension vendor-name="tt" key="class-column" value="none"/>
<field name="personId" primary-key="true">
<extension vendor-name="tt" key="data-column" value="PID"/>
</field>-
<field name="keyProtocols">
<collection element-type="Protocol"/>
<extension vendor-name="tt" key="inverse" value="keyPersons"/>
<extension vendor-name="tt" key="table" value="KeyPersonnel"/>
<extension vendor-name="tt" key="protocolId-data-column"
value="int_protocol"/>
<extension vendor-name="tt" key="personId-ref-column" value="PID"/>
</field>
</class>
The assignment works fine beetwen New Persistent Protocol and Persons, but
when ever I try to add new assignment between existing protocol and person:
void updateProtocol(PersistenceManager pm){
Extent e = pm.getExtent (Person.class, true);
Query query = pm.newQuery (Person.class, e, "fname == \"Alex\"");
Collection collection = (Collection) query.execute();
Iterator i = collection.iterator ();
Person alex = (Person)i.next();
System.out.println("Person to assign" + alex);
e = pm.getExtent (Protocol.class, true);
query = pm.newQuery (Protocol.class, e, "projectTitle == \"This is
JDO test N1\"");
collection = (Collection) query.execute();
i = collection.iterator ();
Protocol firstProtocol = (Protocol)i.next();
try {
pm.currentTransaction().begin();
e = pm.getExtent (Person.class, true);
query = pm.newQuery (Person.class, e, "fname == \"Brian\"");
collection = (Collection) query.execute();
i = collection.iterator ();
while (i.hasNext ())
firstProtocol.addKeyPerson((Person)(i.next()));/*Exception
here!*/
pm.currentTransaction().commit();
} catch (Exception ex) {
pm.currentTransaction().rollback();
ex.printStackTrace(System.out);
I have following exception:
javax.jdo.JDOUserException: The given element "
=======Person=======
First Name: Brian
Last Name: Agricola
Phone: null
Email: null
====================" does not meet the requirements for the container.
at
com.solarmetric.kodo.util.SecondClassObjects.checkValue(SecondClassObjects.j
ava:224)
at com.solarmetric.kodo.util.ProxyLinkedList.add(ProxyLinkedList.java:71)
at peacetech.nih.nhlbi.iasp.dao.Person.addKeyProtocol(Person.java:176)
at peacetech.nih.nhlbi.iasp.dao.Protocol.addKeyPerson(Protocol.java:147)
at peacetech.nih.nhlbi.iasp.IASPTest.updateProtocol(IASPTest.java:142)
at peacetech.nih.nhlbi.iasp.IASPTest.updateProtocol(IASPTest.java:110)
at peacetech.nih.nhlbi.iasp.IASPTest.runTest(IASPTest.java:28)
at peacetech.nih.nhlbi.iasp.IASPTest.main(IASPTest.java:22)
I have the same problem also for one to many.
Can you help me with it?
Thanks,
Kirill.

I have following two classes with many-to-many case:
public class Protocol {
private long protocolId;
private final Collection keyPersons = new ArrayList();
public void addKeyPerson(Person person) {
person.addKeyProtocol(this);
public void removeKeyPerson(Person person) {
person.removeKeyProtocol(this);
public class Person {
private long personId;
private final Collection keyProtocols = new ArrayList();
public void addKeyProtocol(Protocol protocol) {
protocol.getKeyPersonsCollection().add(this);
keyProtocols.add(protocol);
public void removeKeyProtocol(Protocol protocol) {
protocol.getKeyPersonsCollection().remove(this);
keyProtocols.remove(protocol);
The meta data is:
<?xml version="1.0"?>
<jdo>
<package name="peacetech.nih.nhlbi.iasp.dao">
<class name="Protocol" identity-type="application"
objectid-class="peacetech.nih.nhlbi.iasp.dao.oid.ProtocolOid">
<extension vendor-name="tt" key="table" value="protocol"/>
<extension vendor-name="tt" key="pk-column" value="int_protocol"/>
<extension vendor-name="tt" key="lock-column" value="none"/>
<extension vendor-name="tt" key="class-column" value="none"/>
<field name="protocolId" primary-key="true">
<extension vendor-name="tt" key="data-column" value="int_protocol"/>
</field>
<field name="keyPersons">
<collection element-type="Person"/>
<extension vendor-name="tt" key="inverse" value="keyProtocols"/>
<extension vendor-name="tt" key="table" value="KeyPersonnel"/>
<extension vendor-name="tt" key="personId-data-column" value="PID"/>
<extension vendor-name="tt" key="protocolId-ref-column"
value="int_protocol"/>
</field>
</class>
<class name="Person" identity-type="application"
objectid-class="peacetech.nih.nhlbi.iasp.dao.oid.PersonOid">
<extension vendor-name="tt" key="table" value="Personnel"/>
<extension vendor-name="tt" key="pk-column" value="PID"/>
<extension vendor-name="tt" key="lock-column" value="none"/>
<extension vendor-name="tt" key="class-column" value="none"/>
<field name="personId" primary-key="true">
<extension vendor-name="tt" key="data-column" value="PID"/>
</field>-
<field name="keyProtocols">
<collection element-type="Protocol"/>
<extension vendor-name="tt" key="inverse" value="keyPersons"/>
<extension vendor-name="tt" key="table" value="KeyPersonnel"/>
<extension vendor-name="tt" key="protocolId-data-column"
value="int_protocol"/>
<extension vendor-name="tt" key="personId-ref-column" value="PID"/>
</field>
</class>
The assignment works fine beetwen New Persistent Protocol and Persons, but
when ever I try to add new assignment between existing protocol and person:
void updateProtocol(PersistenceManager pm){
Extent e = pm.getExtent (Person.class, true);
Query query = pm.newQuery (Person.class, e, "fname == \"Alex\"");
Collection collection = (Collection) query.execute();
Iterator i = collection.iterator ();
Person alex = (Person)i.next();
System.out.println("Person to assign" + alex);
e = pm.getExtent (Protocol.class, true);
query = pm.newQuery (Protocol.class, e, "projectTitle == \"This is
JDO test N1\"");
collection = (Collection) query.execute();
i = collection.iterator ();
Protocol firstProtocol = (Protocol)i.next();
try {
pm.currentTransaction().begin();
e = pm.getExtent (Person.class, true);
query = pm.newQuery (Person.class, e, "fname == \"Brian\"");
collection = (Collection) query.execute();
i = collection.iterator ();
while (i.hasNext ())
firstProtocol.addKeyPerson((Person)(i.next()));/*Exception
here!*/
pm.currentTransaction().commit();
} catch (Exception ex) {
pm.currentTransaction().rollback();
ex.printStackTrace(System.out);
I have following exception:
javax.jdo.JDOUserException: The given element "
=======Person=======
First Name: Brian
Last Name: Agricola
Phone: null
Email: null
====================" does not meet the requirements for the container.
at
com.solarmetric.kodo.util.SecondClassObjects.checkValue(SecondClassObjects.j
ava:224)
at com.solarmetric.kodo.util.ProxyLinkedList.add(ProxyLinkedList.java:71)
at peacetech.nih.nhlbi.iasp.dao.Person.addKeyProtocol(Person.java:176)
at peacetech.nih.nhlbi.iasp.dao.Protocol.addKeyPerson(Protocol.java:147)
at peacetech.nih.nhlbi.iasp.IASPTest.updateProtocol(IASPTest.java:142)
at peacetech.nih.nhlbi.iasp.IASPTest.updateProtocol(IASPTest.java:110)
at peacetech.nih.nhlbi.iasp.IASPTest.runTest(IASPTest.java:28)
at peacetech.nih.nhlbi.iasp.IASPTest.main(IASPTest.java:22)
I have the same problem also for one to many.
Can you help me with it?
Thanks,
Kirill.

Defining a many-to-many relationship with CMP EJBs : does it work for you

Curious to know whether someone has been able to set up a many to many relationship between two entity beans.
I have been struggling with this for days now and I can't get it to work.
In my test project I have two entity beans, resp. Consultant and Solution.
Consultant has a cmr field called 'solutions', which is a collection object from the opposite side (Solution).
This is the source of the ejb-jar.xml file
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-jar PUBLIC "-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN" "http://java.sun.com/dtd/ejb-jar_2_0.dtd">
<ejb-jar>
     <description>EJB JAR description</description>
     <display-name>EJB JAR</display-name>
     <enterprise-beans>
          <session>
               <ejb-name>ProfilerBean</ejb-name>
               <home>com.atosorigin.tcc.testing.ejbses.profiling.ProfilerHome</home>
               <remote>com.atosorigin.tcc.testing.ejbses.profiling.Profiler</remote>
               <local-home>com.atosorigin.tcc.testing.ejbses.profiling.ProfilerLocalHome</local-home>
               <local>com.atosorigin.tcc.testing.ejbses.profiling.ProfilerLocal</local>
               <ejb-class>com.atosorigin.tcc.testing.ejbses.profiling.ProfilerBean</ejb-class>
               <session-type>Stateless</session-type>
               <transaction-type>Container</transaction-type>
               <ejb-local-ref>
                    <ejb-ref-name>EJBTesting/Solution</ejb-ref-name>
                    <ejb-ref-type>Entity</ejb-ref-type>
                    <local-home>com.atosorigin.tcc.testing.ejbcmp.profiling.SolutionLocalHome</local-home>
                    <local>com.atosorigin.tcc.testing.ejbcmp.profiling.SolutionLocal</local>
                    <ejb-link>SolutionBean</ejb-link>
               </ejb-local-ref>
               <ejb-local-ref>
                    <ejb-ref-name>EJBTesting/Consultant</ejb-ref-name>
                    <ejb-ref-type>Entity</ejb-ref-type>
                    <local-home>com.atosorigin.tcc.testing.ejbcmp.profiling.ConsultantLocalHome</local-home>
                    <local>com.atosorigin.tcc.testing.ejbcmp.profiling.ConsultantLocal</local>
                    <ejb-link>ConsultantBean</ejb-link>
               </ejb-local-ref>
          </session>
          <entity>
               <ejb-name>ConsultantBean</ejb-name>
               <home>com.atosorigin.tcc.testing.ejbcmp.profiling.ConsultantHome</home>
               <remote>com.atosorigin.tcc.testing.ejbcmp.profiling.Consultant</remote>
               <local-home>com.atosorigin.tcc.testing.ejbcmp.profiling.ConsultantLocalHome</local-home>
               <local>com.atosorigin.tcc.testing.ejbcmp.profiling.ConsultantLocal</local>
               <ejb-class>com.atosorigin.tcc.testing.ejbcmp.profiling.ConsultantBean</ejb-class>
               <persistence-type>Container</persistence-type>
               <prim-key-class>java.lang.String</prim-key-class>
               <reentrant>False</reentrant>
               <cmp-version>2.x</cmp-version>
               <abstract-schema-name>Consultant</abstract-schema-name>
               <cmp-field>
                    <field-name>firstname</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>lastname</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>country</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>id</field-name>
               </cmp-field>
               <primkey-field>id</primkey-field>
               <query>
                    <query-method>
                         <method-name>findBySolution</method-name>
                         <method-params>
                              <method-param>java.lang.String</method-param>
                         </method-params>
                    </query-method>
                    <ejb-ql>SELECT Object(c) FROM Consultant AS c,
                    IN(c.solutions) s WHERE s.id = ?1 </ejb-ql>
               </query>
          </entity>
          <entity>
               <ejb-name>SolutionBean</ejb-name>
               <home>com.atosorigin.tcc.testing.ejbcmp.profiling.SolutionHome</home>
               <remote>com.atosorigin.tcc.testing.ejbcmp.profiling.Solution</remote>
               <local-home>com.atosorigin.tcc.testing.ejbcmp.profiling.SolutionLocalHome</local-home>
               <local>com.atosorigin.tcc.testing.ejbcmp.profiling.SolutionLocal</local>
               <ejb-class>com.atosorigin.tcc.testing.ejbcmp.profiling.SolutionBean</ejb-class>
               <persistence-type>Container</persistence-type>
               <prim-key-class>java.lang.String</prim-key-class>
               <reentrant>False</reentrant>
               <cmp-version>2.x</cmp-version>
               <abstract-schema-name>Solution</abstract-schema-name>
               <cmp-field>
                    <field-name>description</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>name</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>parent</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>id</field-name>
               </cmp-field>
               <primkey-field>id</primkey-field>
               <query>
                    <query-method>
                         <method-name>findChildSolutions</method-name>
                         <method-params>
                              <method-param>java.lang.String</method-param>
                         </method-params>
                    </query-method>
                    <ejb-ql>SELECT Object(s) FROM Solution AS s WHERE
                    s.parent = ?1</ejb-ql>
               </query>
               <query>
                    <query-method>
                         <method-name>findTopLevelSolutions</method-name>
                         <method-params/>
                    </query-method>
                    <ejb-ql>Select Object(s) FROM Solution AS s WHERE
                    (s.parent = 'none')</ejb-ql>
               </query>
          </entity>
     </enterprise-beans>
     <relationships>
          <ejb-relation>
               <description>A consultant may have one or more areas of expertise</description>
               <ejb-relation-name>Consultant_Solutions</ejb-relation-name>
               <ejb-relationship-role>
                    <ejb-relationship-role-name>com.atosorigin.tcc.testing.ejbcmp.profiling.ConsultantBean</ejb-relationship-role-name>
                    <multiplicity>Many</multiplicity>
                    <relationship-role-source>
                         <ejb-name>ConsultantBean</ejb-name>
                    </relationship-role-source>
                    <cmr-field>
                         <cmr-field-name>solutions</cmr-field-name>
                         <cmr-field-type>java.util.Collection</cmr-field-type>
                    </cmr-field>
               </ejb-relationship-role>
               <ejb-relationship-role>
                    <ejb-relationship-role-name>com.atosorigin.tcc.testing.ejbcmp.profiling.SolutionBean</ejb-relationship-role-name>
                    <multiplicity>Many</multiplicity>
                    <relationship-role-source>
                         <ejb-name>SolutionBean</ejb-name>
                    </relationship-role-source>
               </ejb-relationship-role>
          </ejb-relation>
     </relationships>
     <assembly-descriptor>
          <container-transaction>
               <description>container-transaction</description>
               <method>
                    <ejb-name>SolutionBean</ejb-name>
                    <method-name>*</method-name>
               </method>
               <method>
                    <ejb-name>ProfilerBean</ejb-name>
                    <method-name>*</method-name>
               </method>
               <method>
                    <ejb-name>ConsultantBean</ejb-name>
                    <method-name>*</method-name>
               </method>
               <trans-attribute>Required</trans-attribute>
          </container-transaction>
     </assembly-descriptor>
</ejb-jar>
I created a stateless session bean as a business facade for the two entity beans. I then created a webservice to test the beans.
What works :
- create a consultant
- get a consultant
- create a solution
- get a solution
(basically everything that doesn't involve the relationship field.
However, what doesn't work is the method call assignSolution:
- assign solution : this is implemented as follows
Business Method.
     public void assignSolution(String consultantID, String solutionID)
          throws ProfilingException {
          // TODO : Implement
          ConsultantLocal cons = null;
          SolutionLocal sol = null;
          try {
               cons = consHome.findByPrimaryKey(consultantID);
               sol = solHome.findByPrimaryKey(solutionID);
               Collection solutions = cons.getSolutions();
               solutions.add(sol);
               //sol.getConsultants().add(cons);
          } catch (FinderException ex) {
               ex.printStackTrace();
               throw new ProfilingException("failed to retrieve data from DB", ex);
As you can see I am trying to use the CM Relationship in this methhod. Adding the solution to a consultant should be as simple as adding a solution object to the collection retrieved with the getSolutions accessor. The Container is expected to persist the information in my MAXDB database.
However this doesn't happen.
The ORM details as defined in the persistent.xml follows :
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE persistent-ejb-map SYSTEM "persistent.dtd">
<persistent-ejb-map>
     <locking
          type="Table"/>
     <db-properties>
          <data-source-name>TCC_PORTAL_PROFILER</data-source-name>
          <database-vendor
               name="SAPDB"/>
     </db-properties>
     <entity-beans>
          <entity-bean>
               <ejb-name>ConsultantBean</ejb-name>
               <table-name>PFL_CONSULTANTS</table-name>
               <field-map
                    key-type="NoKey">
                    <field-name>firstname</field-name>
                    <column>
                         <column-name>FIRSTNAME</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>lastname</field-name>
                    <column>
                         <column-name>LASTNAME</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>country</field-name>
                    <column>
                         <column-name>COUNTRY</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="PrimaryKey">
                    <field-name>id</field-name>
                    <column>
                         <column-name>ID</column-name>
                    </column>
               </field-map>
               <finder-descriptor>
                    <method-name>findBySolution</method-name>
                    <method-params>
                         <method-param>java.lang.String</method-param>
                    </method-params>
                    <load-selected-objects
                         lock="read"/>
               </finder-descriptor>
          </entity-bean>
          <entity-bean>
               <ejb-name>SolutionBean</ejb-name>
               <table-name>PFL_SAPSOLUTIONS</table-name>
               <field-map
                    key-type="NoKey">
                    <field-name>description</field-name>
                    <column>
                         <column-name>DESCRIPTION</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>name</field-name>
                    <column>
                         <column-name>NAME</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>parent</field-name>
                    <column>
                         <column-name>PARENTID</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="PrimaryKey">
                    <field-name>id</field-name>
                    <column>
                         <column-name>ID</column-name>
                    </column>
               </field-map>
               <finder-descriptor>
                    <method-name>findChildSolutions</method-name>
                    <method-params>
                         <method-param>java.lang.String</method-param>
                    </method-params>
                    <load-selected-objects
                         lock="read"/>
               </finder-descriptor>
               <finder-descriptor>
                    <method-name>findTopLevelSolutions</method-name>
                    <method-params/>
                    <load-selected-objects
                         lock="read"/>
               </finder-descriptor>
          </entity-bean>
     </entity-beans>
     <relationships>
          <table-relation>
               <help-table>PFL_CONS_SOL_MAP</help-table>
               <table-relationship-role
                    key-type="PrimaryKey">
                    <ejb-name>ConsultantBean</ejb-name>
                    <cmr-field>solutions</cmr-field>
                    <fk-column>
                         <column-name>CONSULTANTID</column-name>
                         <pk-field-name>id</pk-field-name>
                    </fk-column>
               </table-relationship-role>
               <table-relationship-role
                    key-type="PrimaryKey">
                    <ejb-name>SolutionBean</ejb-name>
                    <fk-column>
                         <column-name>SOLUTIONID</column-name>
                         <pk-field-name>id</pk-field-name>
                    </fk-column>
               </table-relationship-role>
          </table-relation>
     </relationships>
</persistent-ejb-map>
The error in the default trace file when calling the method states, there is an "inconsistency in the number of primary keys". Details follow.
#1.5#000F1F188E5C004400000000000010480003E76C80EFD57A#1098880364327#com.sap.engine.services.ejb#com.atosorigin.tcc/EJBCMPProfilingTest#com.sap.engine.services.ejb#Guest#2####4d2b2370281411d9a40d000f1f188e5c#SAPEngine_Application_Thread[impl:3]_31##0#0#Error##Java###
[EXCEPTION]
#1#com.sap.engine.services.ejb.exceptions.BaseRemoteException: Exception in method assignSolution.
     at com.atosorigin.tcc.testing.ejbses.profiling.ProfilerObjectImpl0.assignSolution(ProfilerObjectImpl0.java:822)
     at com.atosorigin.tcc.testing.ejbses.profiling.Profiler_Stub.assignSolution(Profiler_Stub.java:533)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
     at java.lang.reflect.Method.invoke(Method.java:324)
     at com.sap.engine.services.ejb.session.stateless_sp5.ObjectStubProxyImpl.invoke(ObjectStubProxyImpl.java:187)
     at $Proxy73.assignSolution(Unknown Source)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
     at java.lang.reflect.Method.invoke(Method.java:324)
     at com.sap.engine.services.webservices.runtime.EJBImplementationContainer.invokeMethod(EJBImplementationContainer.java:126)
     at com.sap.engine.services.webservices.runtime.RuntimeProcessor.process(RuntimeProcessor.java:146)
     at com.sap.engine.services.webservices.runtime.RuntimeProcessor.process(RuntimeProcessor.java:68)
     at com.sap.engine.services.webservices.runtime.servlet.ServletDispatcherImpl.doPost(ServletDispatcherImpl.java:92)
     at SoapServlet.doPost(SoapServlet.java:51)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
     at com.sap.engine.services.servlets_jsp.server.HttpHandlerImpl.runServlet(HttpHandlerImpl.java:385)
     at com.sap.engine.services.servlets_jsp.server.HttpHandlerImpl.handleRequest(HttpHandlerImpl.java:263)
     at com.sap.engine.services.httpserver.server.RequestAnalizer.startServlet(RequestAnalizer.java:339)
     at com.sap.engine.services.httpserver.server.RequestAnalizer.startServlet(RequestAnalizer.java:317)
     at com.sap.engine.services.httpserver.server.RequestAnalizer.invokeWebContainer(RequestAnalizer.java:810)
     at com.sap.engine.services.httpserver.server.RequestAnalizer.handle(RequestAnalizer.java:238)
     at com.sap.engine.services.httpserver.server.Client.handle(Client.java:92)
     at com.sap.engine.services.httpserver.server.Processor.request(Processor.java:147)
     at com.sap.engine.core.service630.context.cluster.session.ApplicationSessionMessageListener.process(ApplicationSessionMessageListener.java:37)
     at com.sap.engine.core.cluster.impl6.session.UnorderedChannel$MessageRunner.run(UnorderedChannel.java:71)
     at com.sap.engine.core.thread.impl3.ActionObject.run(ActionObject.java:37)
     at java.security.AccessController.doPrivileged(Native Method)
     at com.sap.engine.core.thread.impl3.SingleThread.execute(SingleThread.java:94)
     at com.sap.engine.core.thread.impl3.SingleThread.run(SingleThread.java:162)
Caused by: com.sap.engine.services.applocking.exception.SAPAppLockingIllegalArgumentException: Inconsistency in number of primary keys
     at com.sap.engine.services.applocking.TableLockingImpl.getArgument(TableLockingImpl.java:385)
     at com.sap.engine.services.applocking.TableLockingImpl.lock(TableLockingImpl.java:128)
     at com.sap.engine.services.applocking.TableLockingImpl.lock(TableLockingImpl.java:138)
     at com.sap.engine.services.ejb.entity.pm.lock.TableLockingSystem.write(TableLockingSystem.java:82)
     at com.sap.engine.services.ejb.entity.pm.PersistentM2M.create(PersistentM2M.java:172)
     at com.sap.engine.services.ejb.entity.pm.PersistentCacheM2M.add(PersistentCacheM2M.java:197)
     at com.sap.engine.services.ejb.entity.pm.multiple.CollectionM2M.add(CollectionM2M.java:57)
     at com.atosorigin.tcc.testing.ejbses.profiling.ProfilerBean.assignSolution(ProfilerBean.java:201)
     at com.atosorigin.tcc.testing.ejbses.profiling.ProfilerObjectImpl0.assignSolution(ProfilerObjectImpl0.java:771)
     ... 32 more
I can't figure out what the problem is with the ORM mapping defined.
On the database level I have three tables. Consultant maps to PFL_CONSULTANT, Solution to PFL_SAPSOLUTIONS. The third table PFL_CONS_SOL_MAP is the help table used for the relationship (having two fields, which are in fact foreign keys from the other two tables to express the assignment of solutions to consultants (where a consultant can have one or more solutions).
ps. : I am running Netweaver Developer Workplace (Netweaver 2004, at stack level 5)
Message was edited by: Theo Paesen

Hm, after disabling 'automatic locking' it works.

Many-to-many performance issue

I realize that many-to-many joins have been discussed before (yes, I looked through many threads), but I'm having a slight variation on the issue. Our data warehouse has been functioning for a couple of years now, but we're now experiencing a dramatic degradation in report performance. I'll tell you everything I know and what I've tried. My hope is that someone will have an idea that hasn't occurred to me yet.
The troubling data links deal with accounts and account_types. Each transaction will have one account, but each account can have multiple account_types and each account_type is made up of multiple accounts. It ends up looking like this:
Transaction_cube --< account_dimension >--< account_type_table
Given the many-to-many relationship between account and account_type, this is the only architecture I could come up with that will maintain data integrity in the transaction cube.
I know that this is the cause of the performance issues because the reports run normally when this is removed. The volume of data obviously increases over time, but the problem appeared very suddenly -- not a gradual degradation that one would expect from a volume issue. The cube is partitioned by year and we're a little below last year's growth.
The other fact to throw in is that the account_type table did increase in size by an additional 30% when we first noticed the problem. However, the business was able to go back and remove half of the account_types (unused types) so now the table has fewer rows than it had before we noticed the problem (~15k rows in the account_type table).
We have tried pinning the table so that it remain in memory, but that did not help. I tried creating a materialized view combining accounts and account_types with a similar lack of improvement. I've tried adding indexes, but there is still a full-table scan. All database objects are analyzed nightly after the data load is completed.
I'm fresh out of ideas at this point. Any suggestions and/or ideas would be greatly appreciated.

I've thought about that. What it would mean would be aprox. 20 additional columns for each of the different account_types. Unfortunately, that would also mean that all the reports that use the account_type would have to have a condition:
WHERE acct_type1='Income Stmt." OR acct_type2='Income Stmt." OR ....
Since the account_types are not set up in a hierarchy and there must be only one row for account, I'm not sure that this is a feasible solution.
Thank you for the suggestion.

Master - detail block (many-to-many)

Hello, , I have 2 tables:
1-(parts)its primary key : p_id
2-(suppliers)its primary key : s_id
and they have many-to-many relationship between them .
the table Resulted from the relationship is(part_supp)
How can I create master-detail block Based on this relationship.In other words, which of tables will be the master and which of them well be detail.
I am using form 6i ..
please help.....

M3ATH wrote:
Hello, , I have 2 tables:
1-(parts)its primary key : p_id
2-(suppliers)its primary key : s_id
and they have many-to-many relationship between them .Many to many relation between two table isn't a good database design. You have to a junction table between them.
the table Resulted from the relationship is(part_supp)Is this your junction table(part_supp) ?
>
How can I create master-detail block Based on this relationship.In other words, which of tables will be the master and which of them well be detail.If part_supp is your junction table between parts and suppliers then, try this..
Use the junction table as a hidden block, then establish a standard Forms relation between
Parts and (hidden)part_supp then between part_supp and suppliersHope this helps

Many-to-many question

Just asking for some help with some search terms, as I know that this topic has been argued out somewhere. I just haven't been able to find it:
If I'm setting up a cross-reference/junction table in order to fulfill a many-to-many requirement, should I create a technical key as a primary key with a unique index on the combined foreign keys? Or should I make the combination of the foreign keys the primary key?
Our newest standards force a technical key on all tables, and one of the Developers is asking why that's necessary on a cross-reference table. I've searched on "cross reference table primary key", "junction table primary key". Most answers suggesting a technical key are due to database performance issues that can be solved with it (not suggested for that reason for Oracle that I've found yet).
--=Chuck

>
If I'm setting up a cross-reference/junction table in order to fulfill a many-to-many requirement, should I create a technical key as a primary key with a unique index on the combined foreign keys? Or should I make the combination of the foreign keys the primary key?
>
Assuming that each of your foreign keys is a surrogate key and not an actual data value, I have to agree with Dan on this one.
The two primary attributes that a key value should have are: 1) it should be unique and 2) it should have no inherent meaning.
By 'no inherent meaning' I mean it should NOT be a data value or have any meaning whatsoever attached to its value. If the value were to change it would have no impact at all on the actual data though naturally the value has to be changed the same everywhere it is used.
A classic example in the U.S. is social security number. It should NOT be used as a key even though it might be considered a 'natural' key.
The value is a data item that has meaning and is subject to change if for no other reason than typographical error. It is the problems involved in making changes to data items used as keys that surrogate keys are intended to prevent.
A surrogate key (even a sequence) has no inherent meaning. If a value of 2 is being used in a system and, unknown to you, someone changes the value to a 3 everywhere in your system that it is used you will never notice it.
I have seen no standard suggesting that multi-column surrogate keys are inappropriate. Your intersect table can use the combination of the foreign keys as the primary key and fulfill the contract of using surrogate keys.
Sven suggested this
>
For example you later discover that you want a detail table for your joined table. Then the detail table would need only one column as a foreign key constraint, instead of two (which can have major performance implications).
>
If if was desired to meet that future requirement by using one column you can easily do so by adding a new column specifically for that purpose without any impact whatsoeve on the existing system.
As for this possible architecture change
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Or you add some third column to include into the uniqueness logic.
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Well that requirement is a fundamental change to your existing one. The existing requirement is that the combination of the two foreign keys should be unique. It is not clear if Sven was suggesting that that requirement is no longer valid or if rather suggesting that there is no an ADDITIONAL requirement that those two values as well as a third should also be unique.
If you need to implement uniqueness for the two values you currently have as well as for those combined with a third value that would be better implemented by creating yet another INTERSECT table specifically for that purpose and leave the existing intersect table in place. That architecture approach expands the data model without disrupting the existing one.
The main design goal, in my opinion, should always be to produce a design which most easily meets current requirements without foreclosing the ability to meet unknown future requirements.

Many-to-many relationship - show all values

Hi,
I'm building a cube in 2008R2 and have a many-to-many relationship through a bridging table but when displaying the results it is effectively an inner join and I would like to see a full outer join with the unknown rows set to "unknown".
I've managed to achieve this by doing a full outer join in the view that creates my bridging table and having an unknown member in my dimensions but then when I added in a dimension that wasn't directly related to the bridging table the unknown rows
were removed again. I was able to get past this by adding a row to my fact table with all the keys set to unknown and the metrics set to zero.
Whilst this works it really does not seem like an ideal solution, especially as previously empty metrics are now returning a zero.
Is there any way to achieve this in SSAS? Perhaps in the way unknown members are processed?
Thanks,

cccparkhill,
What you did is the only way to achieve what you want.
In cubes you connect Dimensions throw Facts. By definition dimensions are
“How do business people describe the data that
results from the business process?”
and facts are “What are we measuring?”, noting the underlined
we can understand that _normally and usually_ the relation between the dimensions and the facts represent incidents happened in the real world ... the way you approach, think, and deal with dimensions and facts in cubes is different than dealing with tables
in normal relational transnational database.
Personally I do what you did when I want to achieve "Left join"
Please mark this reply as the answer
or vote as helpful, as appropriate, to make it useful for other readers

Additional properties on Many-to-Many relation

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