Many to many relationships (Again)
Hello,
There was a posting on above subject.
Re: Many to many relationships between Fact and Dimension
They asked to look chapter 3 in the user's guide... <http://download.oracle.com/docs/pdf/B10996_01.pdf>. chapter 3 talks about defining Oracle Data Objects. I could find above subject in chapter 3 .
Here is our situation We are using OWB 9.2.0.2.8. We are in a situation to build ETL from denormalized (relational tables) source to normalized target (relational tables). It is not a data warehouse situation. It could be a reverse of data warehouse. As given below
Supplier >--------------------<Item
becomes Supplier ------<supp_item.>--------------Item after many to many resolution, Where supp_item is interface table.
We were able build Supplier and Item through seprate mapping. I could build supp_item through post mapping process. I look for alternate thought as well.
We are using separate sequence number for Supplier , Item and supp_item. The sequences will be surrogate keys such as Supplier ( Suppseq(PK)), Item (Itemseq (PK)) and supp_item(suppitemseq (PK)) Here is the sample
Supplier
001|S001
002|S002
003|S003
004|S004
Item
001|I001
002|I002
003|I003
Supp_item (Suppseq|ItemSeq)
001|002 --- S001 I002
001003 -----S001 I003
001|004 ----- S001 I 004
002|002 ---- S 002 I002
002|003 ---- S 002 I003
003|001 --- S 003 I 003
003|003 --- S 003 I 003
Did any body face such situation? What is the best way to create a mapping (single map or multiple map with processflow sequence) for this situation?
Let me know the steps exercised in OWB for this situation.
I appreciate your help.
Regards
Ram
Hi Ram,
The easiest way to do this, would be to:
- Load supplier in one mapping and generate the surrogate key.
- Load item another (or the same) mapping and generate the surrogate key.
- Load supplier_item in its own separate mapping, using a key lookup (or join) to (with) the supplier and item tables.
Needless to say, you should create unique keys on the natural key of the supplier and item tables, to enable quick index-based lookups and make sure you get one unique value for every value of the natural key.
Hope this helps,
Mark.
Similar Messages
-
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 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 -
Hierarchical query with many-to-many relationship
I have read with interest the creative solutions to complex hierarchical queries posted previously; they have been instructive but have not quite addressed this scenario.
We have a hierarchy table H, with columns for ID, name, parentID, and other attributes.
Within this table are a number of independent hierarchies, each existing for a different purpose.
We have a master list of hierarchies in table T which describes the purpose of each hierarchy, provides some default attributes which the nodes can inherit, and stores a unique id for each hierarchy and a pointer to the root node of the corresponding hierarchy in table H.
We have a master list of items M, with identically named columns to those in H, along with many other attributes.
The members of table M ALL belong to EACH of the Hierarchies. So we have a link table I to define the intersection of H and M.
So the leaf nodes of H are really containers for the list of elements from M which may be attached to them.
The universe of M is very volatile, with new members being added, old ones deleted, and existing ones being reclassified frequently from node to node within each hierarchy. Since the hierarchies have to be built to handle every possible scenario, so that the members of M can always find a suitable node to reside in, quite often, in fact more often than not, the majority of leaf nodes for each hierarchy are empty at any given moment.
Therefore, although we always know the root sector of a given hierarchy and can traverse downwards from there, if we worked our way up from the intersection table, we could eliminate up to 70% of the nodes of any given hierarchy from further consideration, as they don't need to be (in fact, must not be) included in reports.
As implied by the above, rows in M are structurally similar (in terms of columns, but not in any real world sense) and are a superset of rows in H. But combining them into the one table doesn't seem to help the reporting process due to the many-to-many relationship which prevents the ID/parentID relationship from being carried through to this level.
There are a number of other considerations of which the most pertinent is that the people using this database generally have an interest in only a subset of the master list of items in M. This relationship is also dynamic but important enough and rigid enough that another link table P exists to combine the Users in table U with the subset of M in which they are interested. (The users are also grouped into hierarchies of a totally different nature, but this aspect is secondary for now.)
The reporting is reasonably straightforward for any single combination of User and Hierarchy; they want to see all the items they are interested in, listed in hierarchical sequence, totalled on change of level with the individual items M listed beneath the nodes of H. This is unfortunately required in real time, so retrieval performance is paramount.
Some statistics might help to determine the optimum approach:
The largest hierarchy has 10,000 nodes. The smallest about 100.
The largest would have 70% or more of its nodes unused at any point in time, and even the smallest would have 25% unused.
The hierarchies tend to be broad rather than deep, the maximum number of levels being about 5; but the larger ones should be twice as deep as this if performance was not compromised.
There are dozens of hierarchies, but it may be possible to sharply reduce this number by exploiting the Order Siblings By clause.
The number of rows in M varies between 500,000 and 50,000; depending upon how long historical data is retained on-line (and performance permitting, it would be retained indefinitely).
The number of users varies between 1000 and 2000 but the range of M in which they are interested varies greatly; from as few as 100 to as many as 10,000+. So it is almost always worth beginning by eliminating the items in which they are not interested, implying once again that the hierarchy should be traversed upwards rather than down from the root.
The current system is very old and survives by a tactic of building what are essentially materialised views of the database structure for each user overnight using, ahem, non-relational technology. This is inefficient and not easily scaled (but it works) and hence this redevelopment project needs to (a) work, and (b) work better and faster.
I am happy to provide some DDL scripts if that helps explain the problem better than this narrative.
I can't help feeling that the solution lies in somehow extending the hierarchical query past the many-to-many link table so that the Master list can be merged directly into the hierarchy such that the M items become the leaf nodes rather than the design outlined above - but I don't know how to do that. But I am sure everyone reading this does! :)
All advice appreciated. Database version is not an issue; we are currently using version 10XE for experimentation, but production usage could be on 11 if that contains helpful features.
Thank you
CSHi,
ChrisS. wrote:
I am happy to provide some DDL scripts if that helps explain the problem better than this narrative.Yes, please do.
The problem seems interesting, I'm sure many people here (including myself) are willing to help you in this matter.
So yes, post DDL for the tables, as well as INSERTs to populate them with representative data. Please also include the output you require along with detailed explanations about the logic to get it.
Don't forget to put lines of code between {code} tags in order to preserve formatting and readability, like this :
SELECT sysdate FROM dual;Thanks. -
Many to Many relationship betwee dimension and fact tanle
Hello Gurus,
I have a little question about many to many realtionship between fact and dimension table. The situation is as follows.
Consider there is a fact table F1 and two dimension tables D1 and D2. D1 is joined to F1 with 1 to many relationship. D1 is joined to D2 with again one to many relationship ( Note: D1:D2 = 1:N and D1:F1 = 1:N). I am able to model this by merging D1 and D2 into one dimension table in BMM layer by adding them as logical table sources and creating logical table source join. I have built simple reports and the data returnned is fine. However, I would just like to know what could be the drawbacks of such a model.
We have many other dimesions joined to the fact table and users have access to the answers that means they would could what ever report they feel like. Hence, would just like to know in what cases this model could break which means reports would give wrong data because of a many to many relationship between one of the fact and dimension table.
Thanks in advance.Hello Copter,
Even I had modeled it by reading this link before. In the situation explained by me dimension D1 is doing the job of table Rules ( as explained in link). The model is fine.
However, my point is to undersatnd in which scenerios this model will break. As already explained, the fact table is joined to various other dimensions, there could be situations in which users select columns from various dimensions and facts randomly.
Hence, which are the scenerios where I might get erroneous counts of meassures. Further, if someone feels this model is correct and would not break in any scenerio then please reply. -
Many to many relationship issue
Guys,
How do we deal with the situation where we have many to many relationship between 2 different characteristics?
Thanks,
RGHi,
I assume you are talking about data modeling.
When you are required to decide how to model two Char with many to many relations
1. If you keep them in Same Dimension table the size of the dimension table will be more.
lets say 100 Customers & 100 Materials
Now if you keep them in same dimension..
lets say C1 will have combination of M1 till M100.similarly for other customers
So Total rows in dimension table will be 100x 100 = 10000!!!
It will again be of comparable size to fact table and not recommended.
2.You always try to define them in different dimensions
Now ,You try keeping them in diffrent dimension..in this case Customer dimension will have only 100 rows & Mateial dimension will have only 100 Rows.very small when compared to fact table size.
Hope this helps
Sriman -
One to many relationships in EJB
I have two EBs related by a one to many relationship. The first of these tables is called Student and has studentId as its key. The second of the tables has a composite key made up of studentID, courseID and semesterID.
However, when the tables are generated in NetBeans 5.5, I find that the Course table has studentID as both a primary key and a foreign key.
I am at a loss to understand this as I am new to NetBeans and EJB.
Can anyone advise?
Thanks
Martin O'Shea.
The Student class:
package CBSD_CW;
import java.io.Serializable;
import javax.persistence.*;
import java.util.*;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
@Entity
public class Student_EB implements Serializable {
// Table columns.
@Id
@Column(name = "STUDENT_ID", nullable = false)
private Long studentId; // Student ID. Entity <Student><ID> from file: SampleData.xml.
@Column(name = "FIRST_NAME", length = 50, nullable = true)
private String firstName; // First Name. Entity <Student><FirstName> from file: SampleData.xml.
@Column(name = "LAST_NAME", length = 50, nullable = true)
private String lastName; // Last Name. Entity <Student><LastName> from file: SampleData.xml.
@Column(name = "STUDENT_LEVEL", length = 2, nullable = true)
private String studentLevel; // Student Level. Entity <Student><Level> from file: SampleData.xml.
@Column(name = "PROGRAM_NAME", length = 50, nullable = true)
private String programName; // Program Name. Entity <Student><ProgramName> from file: SampleData.xml.
@Column(name = "PROGRAM_NUMBER", length = 3, nullable = true)
private String programNumber; // Program Number. Entity <Student><ProgramNumber> from file: SampleData.xml.
// 1:M relationship with Course_EB.
@OneToMany(cascade=CascadeType.ALL, mappedBy="student")
private List<Course_EB> courses;
public List<Course_EB> getCourses() {
return courses;
public void setCourses(List<Course_EB> courses) {
this.courses = courses;
// Accessors and mutators.
public Long getId() {
return this.studentId;
public void setId(Long studentId) {
this.studentId = studentId;
public String getFirstName() {
return firstName;
public void setFirstName(String firstName) {
this.firstName = firstName;
public String getLastName() {
return lastName;
public void setLastName(String lastName) {
this.lastName = lastName;
public String getStudentLevel() {
return studentLevel;
public void setStudentLevel(String studentLevel) {
this.studentLevel = studentLevel;
public String getProgramName() {
return programName;
public void setProgramName(String programName) {
this.programName = programName;
public String getProgramNumber() {
return programNumber;
public void setProgramNumber(String programNumber) {
this.programNumber = programNumber;
// Other methods.
public boolean equals(Object obj) {
if (obj == this) {
return (true);
if (!(obj instanceof Student_EB)) {
return (false);
if (obj == null) {
return (false);
Student_EB student = (Student_EB) obj;
return (student.studentId == studentId);
The Course class:
package CBSD_CW;
import javax.persistence.CascadeType;
import javax.persistence.EmbeddedId;
import javax.persistence.Entity;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToOne;
@Entity
public class Course_EB implements java.io.Serializable {
Course_PK course;
// M:1 relationship with Student_EB.
private Student_EB student;
@ManyToOne(cascade=CascadeType.ALL)
@JoinTable(name = "Student_EB", joinColumns= @JoinColumn(name = "STUDENT_ID", referencedColumnName = "studentId"))
public Student_EB getStudent() {
return (student);
public void setStudent(Student_EB student) {
this.student = student;
// Constructor.
public Course_EB() {
// Accessors and mutators.
@EmbeddedId
public Course_PK getCourse_PK () {
return (course);
public void setCourse_PK(Course_PK course) {
this.course = course;
The Course_PK class:
package CBSD_CW;
import javax.persistence.Column;
import javax.persistence.Embeddable;
@Embeddable
public class Course_PK implements java.io.Serializable {
// Table columns.
@Column(name = "STUDENT_ID", length = 4, nullable = false)
private long studentId; // Student ID. Entity <Student><ID> from file: SampleData.xml.
@Column(name = "COURSE_ID", length = 4, nullable = false)
private String courseId; // Course ID. Entity <Student><Course><Number> from file: SampleData.xml.
@Column(name = "SEMESTER_CODE", length = 3, nullable = false)
private String semesterCode; // Semester Code. Entity <Student><Course><SemesterCode> from file: SampleData.xml.
@Column(name = "GRADE", nullable = true)
private char grade; // Grade. Entity <Student><Course><Grade> from file: SampleData.xml.
// Constructors.
public Course_PK() {
public Course_PK(long studentId, long courseid, String semesterCode) {
this.studentId = studentId;
this.courseId = courseId;
this.semesterCode = semesterCode;
// Accessors and mutators.
public long getStudentId() {
return (studentId);
public void setStudentId(long studentId) {
this.studentId = studentId;
public String getCourseId() {
return (courseId);
public void setId(String courseId) {
this.courseId = courseId;
public String getSemesterCode() {
return (semesterCode);
public void setSemesterCode(String semesterCode) {
this.semesterCode = semesterCode;
public char getGrade() {
return (grade);
public void setGrade(char grade) {
this.grade = grade;
// Other methods.
public boolean equals(Object obj) {
if (obj == this) {
return (true);
if (!(obj instanceof Course_PK)) {
return (false);
if (obj == null) {
return (false);
Course_PK course = (Course_PK) obj;
return ((course.studentId == studentId) &&
(course.courseId.equals(courseId)) &&
(course.semesterCode.equals(semesterCode)) &&
(course.grade == grade));
}Because you have field
@Column(name = "STUDENT_ID", length = 4, nullable = false)
private long studentId; // Student ID. Entity <Student><ID> from file: SampleData.xml.In you Course_PK class. As a primary keys.
An again you are joining it in field
@ManyToOne(cascade=CascadeType.ALL)
@JoinTable(name = "Student_EB", joinColumns= @JoinColumn(name = "STUDENT_ID", referencedColumnName = "studentId"))So it is appearing both inPrimary Key and in Foreign Key. -
Merge Two Reports in Excel Analyzer - One To Many Relationship
I want to show AR Data with CO Data - e.g. a bill + Income and it's associated account ssignemnt on the FI/CO side. I want the report to be able to show a cost centre manager to be wary of the income credited to their cost centre when a debtor has been raisedaas they may not fully pay the bill. To do this I'm using the standard DSO for AR & GL line items. Fisrtly I run a query on GL line item data where the user can select from a cost centre variable to look at credits to their cost centre. This produces a list of source documents that are used (via replacement path variable) in a second query. The second GL Query gives me a list of the allocation numbers for those line items. Had to be two queres as there are two GL postings that needed linking (this is because the cost assignment comes from a ceratin acc type and the debtor information comes from another acc type). I then use the allocation number (again via a replacement path variable) to run a third query on the AR data that shows all bills and payments linked to that allocation number. It seems to work ok.
However I have put these three queries in an Excel Analyzer workbook. All the user does is enter a cost centre when running the report. Each query is on a different sheet but what I'd like to do is merge the data on to the one sheet. I want to see the bill and it's payments from the AR data matched up with the cost assignment from the FI/CO data. This would be a one to many relationship e.g. one bill may have it's cost assignment split over more than one cost centre. Is there anyway to do this using simple excel functionality?
So I'd like to see:
Allocation No. 12345 Bill £100 Revenue £50 Cost Centre 1234 £25
Cost Centre 2345 £25
Anybody any ideas?Hi,
Thanks for your answers.
I did explore using infosets but really struggled with joining the data and getting a sensible output. For example where a bill was done in installments I was getting 12 lines (e.g. one for each month) rather than just one. THis meant it looked liked they'd paid twleve times as much etc.
I did also try report to report. Which to my mind worked ok. Except the customer wanted it all in "One" report rather than having to drill down to see data.
I'll try a multiprovider but I'm worried that I'll end up with similar issues as I had when using the infoset.
Cheers
Joel -
Problem with 1-to-many relationship between entity beans
Hi All!
I have two tables TMP_GROUP and TMP_EMPLOYEE with following fields:
TMP_GROUP: ID, CAPTION, COMMENT, STATUS.
TMP_EMPLOYEE: ID, LOGIN, GROUP_ID.
For this tables i create two entity beans GROUP and EMPLOYEE respectively.
The relationship looks like this
descriptor ejb.xml:
<ejb-relation>
<description>description</description>
<ejb-relation-name>employeesOfGroup</ejb-relation-name>
<ejb-relationship-role>
<ejb-relationship-role-name>com.mypackage.GroupBean</ejb-relationship-role-name>
<multiplicity>One</multiplicity>
<relationship-role-source>
<ejb-name>GroupBean</ejb-name>
</relationship-role-source>
<cmr-field>
<cmr-field-name>employees</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.mypackage.EmployeeBean</ejb-relationship-role-name>
<multiplicity>Many</multiplicity>
<relationship-role-source>
<ejb-name>EmployeeBean</ejb-name>
</relationship-role-source>
</ejb-relationship-role>
</ejb-relation>
descriptor persistent.xml:
<table-relation>
<table-relationship-role
key-type="PrimaryKey">
<ejb-name>GroupBean</ejb-name>
<cmr-field>employees</cmr-field>
</table-relationship-role>
<table-relationship-role
key-type="NoKey">
<ejb-name>EmployeeBean</ejb-name>
<fk-column>
<column-name>GROUP_ID</column-name>
<pk-field-name>ejb_pk</pk-field-name>
</fk-column>
</table-relationship-role>
</table-relation>
Now i implement business method:
public Long addEmployee(String login, long groupId) {
Long result;
try {
EmployeeLocal employee = employeeHome.create(login);
GroupLocal group =
groupHome.findByPrimaryKey(new Long(groupId));
Collection employees = group.getEmployees();
employees.add(employee);
result = (Long) employee.getPrimaryKey();
} catch (CreateException ex) {
result = new Long(0);
} catch (FinderException ex) {
result = new Long(0);
return result;
When i call this method from web service, the following exception is raised:
com.sap.engine.services.ejb.exceptions.BaseTransactionRolledbackLocalException: Exception in method com.mypackage.GroupLocalHomeImpl0.findByPrimaryKey(java.lang.Object).
P.S.
1) I have transaction attribute set to "Required" for all methods of all beans
2) I have unique index for each table:
TMP_GROUP_I1: CAPTION
TMP_EMPLOYEE_I1: LOGIN (however i think GROUP_ID must be added here too)
3) I tried many:many relationship with this tables and it works fine
4) I try another implementation of addEmployee method with
EmployeeLocal employee = employeeHome.create(login, groupId);
without using GroupLocal cmr-field and GroupLocalHome findByPrimaryKey method, the result is same error.
Can somebody help me with this problem?
Thanks in advance.
Best regards, Abramov Andrey.gimbal2 wrote:
1: The @JoinColumn on the listOfDepartments collection in Company is wrong. It should be something like this for a bidirectional relationship:
@OneToMany(mappedBy="company") // company is the matching property name in Department
private List <Department> listOfDepartment = new ArrayList<Department>();Note that I removed the fetch configuration; onetomany is fetched lazy by design. Saves some clutter eh.
2: use a Set in stead of a List (hibernate doesn't like lists much in entities and will break when you create slightly more complex entity relations)
3: don't just slap cascades on collections, especially of type ALL. Do it with care. In the many years I've been using JPA I've only had to cascade deletes in very specific situations, maybe once or twice. I never needed any of the other cascade types, they just invite sloppy code if you ask me. When working with persistence you should apply a little precision.I made all changes as you mentioned but still compID in department table shows null value... -
Problem with 1:many relationship between entity beans.
Hi All!
I have two tables TMP_GROUP and TMP_EMPLOYEE with following fields:
TMP_GROUP: ID, CAPTION, COMMENT, STATUS.
TMP_EMPLOYEE: ID, LOGIN, GROUP_ID.
For this tables i create two entity beans GROUP and EMPLOYEE respectively.
The relationship looks like this
descriptor ejb.xml:
<ejb-relation>
<description>description</description>
<ejb-relation-name>employeesOfGroup</ejb-relation-name>
<ejb-relationship-role>
<ejb-relationship-role-name>com.mypackage.GroupBean</ejb-relationship-role-name>
<multiplicity>One</multiplicity>
<relationship-role-source>
<ejb-name>GroupBean</ejb-name>
</relationship-role-source>
<cmr-field>
<cmr-field-name>employees</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.mypackage.EmployeeBean</ejb-relationship-role-name>
<multiplicity>Many</multiplicity>
<relationship-role-source>
<ejb-name>EmployeeBean</ejb-name>
</relationship-role-source>
</ejb-relationship-role>
</ejb-relation>
descriptor persistent.xml:
<table-relation>
<table-relationship-role
key-type="PrimaryKey">
<ejb-name>GroupBean</ejb-name>
<cmr-field>employees</cmr-field>
</table-relationship-role>
<table-relationship-role
key-type="NoKey">
<ejb-name>EmployeeBean</ejb-name>
<fk-column>
<column-name>GROUP_ID</column-name>
<pk-field-name>ejb_pk</pk-field-name>
</fk-column>
</table-relationship-role>
</table-relation>
Now i implement business method:
public Long addEmployee(String login, long groupId) {
Long result;
try {
EmployeeLocal employee = employeeHome.create(login);
GroupLocal group =
groupHome.findByPrimaryKey(new Long(groupId));
Collection employees = group.getEmployees();
employees.add(employee);
result = (Long) employee.getPrimaryKey();
} catch (CreateException ex) {
result = new Long(0);
} catch (FinderException ex) {
result = new Long(0);
return result;
When i call this method from web service, the following exception is raised:
com.sap.engine.services.ejb.exceptions.BaseTransactionRolledbackLocalException: Exception in method com.mypackage.GroupLocalHomeImpl0.findByPrimaryKey(java.lang.Object).
P.S.
1) I have transaction attribute set to "Required" for all methods of all beans
2) I have unique index for each table:
TMP_GROUP_I1: CAPTION
TMP_EMPLOYEE_I1: LOGIN (however i think GROUP_ID must be added here too)
3) I tried many:many relationship with this tables and it works fine
4) I try another implementation of addEmployee method with
EmployeeLocal employee = employeeHome.create(login, groupId);
without using GroupLocal cmr-field and GroupLocalHome findByPrimaryKey method, the result is same error.
Can somebody help me with this problem?
Thanks in advance.
Best regards, Abramov Andrey.I have posted excerpts from my orion-ejb-jar.xml file in this posting: Problem mapping a 1:M relationship between two entity EJBs w/ a compound PK
Sorry for the duplicate postings, but I was getting errors on the submission.
April -
ONE-to-MANY relationship between tables and forms in APEX
I recently started using APEX and I have run into an issue.
I have a ONE-TO-MANY relationship between two tables, A1 and A2, respectively.
A1:
A1_ID
Item
A2:
A2_ID
SubItem
A1_ID
I have 2 forms (lets call it F1 and F2) that I use to capture data for A1 and A2.
On F2, I have the following fields that are setup to capture data:
A2.A1_ID
**A1.Item (this is a drop down that is populated using a SELECT statement where the select uses A1.Item field)
A2.SubItem (user would enter SubItem)
Note: A2.A2_ID is populated using a SEQ
Everytime I pick **A1.Item on F2, is there a way to link to A1 table and display A1.A1_ID for every **A1.Item selected on F2?
If so, I want to store the value captured in F2 for the A1_ID field into A2 table to maintain my 1-to-MANY relationship.
If this will work, how do I go about implementing this solution?
Can someone help me?I think it sounds like you are asking for a Master-Detail form. Try that and see what you get.
chris. -
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 -
Urgent : java bean having bidirectional one to many relationship
Hi,
We have complex requirement in our application.
We need to copy java bean having bidirectional one to many relationship to another javabean having bidirectional one to many relationship..
E.g
Class Basket1 {
public String color;
pubic String type;
public List<Basket1> basketList = new ArrayList()
Class Basket2 {
public String color;
pubic String type;
public List<Basket2> basketList = new ArrayList()
We need to exact copy Basket1 to Basket2. We are in trouble to copy List of child because we do not have how many child Basket1 have of same type..
Can someone help us how we can implement such kind of complex object bidirectional one to many relationship??I can't see anything bidirectional about these relationships. What I can see is a couple of BasketN classes that look identical so I don't know why they both exist, and they both contain lists of themselves as members, which suggests some kind of tree structure. Nothing bidirectional there. I can see tat these things can form circular object graphs but I don't see why you would want to do that.
We need to exact copy Basket1 to Basket2And I don't know what that means. Please explain. -
How to insert data in a one-to-many relationship
How do you insert data into the client, my model entity beans have a one-to-many relationship.
PARENT ENTITY BEAN
PARENT-ID
PARENT-NAME
The ejbCreate(Integer parentID,String name)
CHILD ENTITY BEAN
CHILD-ID
CHILD-NAME
PARENT-ID(foreign key of PARENTID).
ejbCreate(Integer parentID,String name,String foreignparentID)
In a jsp page i collect the parent details and 3 corresponding chld details in a text box.
Can you please tell me how do i proceed from here...
ie. how to i insert data into the entity beans..
Do i pass the child as a collection, and within parents ejbCreate() method do i lookup for the childs home interface and insert one -by -one from the collection.
1. Considering the above example, can some one pls tell how the ejbCreate() mehod signatures, for the parent and child entity beans should be.
2. Pls also show some sample client code as to how to make an insertion.
3. In case you are passing a collection of child data, then in what format does one have to insert into a collection and also how does the container know how to insert the values in the child table , bcoz we are passing as a collection.
4.In case collections cannot be inserted do we need to iterate into the collection in parent's ejbCreate() method, and manually insert into the database of the childtable, thereby creating child entity beans.
Thanks for your time and support...
regards
kartikHi,
3. In this case of course child's ejbCreate(and postCreate) looks like
ejbCreate(Integer childID,String name,ParentLocal parent) {
setId(Id);
setName(name);
ejbPostCreate(Integer childID,String name,ParentLocal parent) {
setParent(parent);
Here you don't need IDs, but it happens only using Locals, not Remotes, if I'm not wrong. Container does it itself.
1. Of course, if you have parent.getChildren() and parent.setChildren() then you don't need any loops, but it should be done anyway in postCreate, because in ejbCreate there no parent exists yet.
Once more 3: example - I'm using JBoss 3.2.5 as EJB container. It has tomcat inside and EJB and JSP+Struts use the same jvm. It means for me that I don't need to use remote interfaces, just locals. And in this case I can implement ejb-relations. So, a have the abstract method parent.getChildren() which returns Collection of ChildLocal - s and method parent.setChildren(Collection childrenLocals) which creates/modifies children by itself.
I have not used remotes for a long time, but as I remember it was not possible to implement ejb-relations using remotes.
regards,
Gio -
In powerpivot we are facing problem in resolving the many-to-many relationship between tables.
Current table schema is:
Having 4 tables-
Bills - columns are- Bill No(primary key)
Billing Fee Table-Fee ID(primary key), Bill Type, Sub Bill Type
FeeList Table-FeeList ID(primary key),Fee ID(Foriegn Key to Billingble),
Bill No(Foriegn Key to Bills)
Payments Table-Pay ID(Primary Key), Bill No(Foriegn Key to Bills)
Bills is the primary table for Feelist Table
and Payments Table -Bill No is the primary key.
Billing Fee Table is primary table for FeeList Table -
Fee ID is the primary key.
To create a pivot table using Payments Table, I need
Bill Type and Sub Bill Type. Hence fetched from
Biling Fee Table to FeeList Table based on the
Fee ID column using RELATED function.
As FeeList Table and Payments Table is having duplicate
Bill Nos, it is not possible to get Bill Type and
Sub Bill Type to Payments Table. I am trying to use LOOKUPVALUE
function to get data based on the Bill No, as there is no direct relationship exists between these two tables.
I have tried using
=LOOKUPVALUE('FeeList Table'[Sub Bill Type], 'FeeList Table'[Bill No], 'Payments Table'[Bill No]) function. But
the lookupvalue function returns an error if a duplicate is found.
Error is as below:
Calculation error in column 'Payments Table'[Sub Bill Type]: A table of multiple values was supplied where a single value was expected.
Kindly assist to resolve this issue.
ThanksHi Rekha,
What should your LOOKUPVALUE return if multiple rows are found in the FeeListTable? By the way it should work if a really finds "duplicates" (i.e. multiple times the same return value) but fails if it returns multiple rows with different values.
If you for example would want to return the first entry that was found, you could try (have not checked in PP for typos):
CALCULATE(MIN('FeeList Table'[Sub Bill Type]),
FILTER('FeeList Table',
'FeeList Table'[Bill No] = 'Payments Table'[Bill No]
Edit: a very nice way to handle Many-to-Many relationships is explained here:
http://blog.gbrueckl.at/2012/05/resolving-many-to-many-relationships-leveraging-dax-cross-table-filtering/
Julian Wissel | BI for NAV @ http://en.navbi.com | Blog @ blog.navida.eu
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