Hi Umesh
I'm glad it worked for you...
As for ResultDescriptor, it's used to give DAS metadata information about
a query result. In most cases, the database will provide the metadata, but
when you are performing some special queries (union is among these special
queries) the metadata will not be available, and then you should provide the
resultDescriptor informing the field, the table and type of the field in
order to DAS properly handle the results. Below is the XSD definition for
resultDesciptor :
<xsd:complexType name="ResultDescriptor">
<xsd:attribute name="columnName" type="xsd:string"/>
<xsd:attribute name="tableName" type="xsd:string"/>
<xsd:attribute name="columnType" type="xsd:string"/>
</xsd:complexType>
Let me know if you have further questions...
On 4/25/07, Umesh Tyagi (utyagi) <[EMAIL PROTECTED]> wrote:
Thanks for the Code. Yes it worked but only after some tweaking in the
SQL query for "testFullOuterJoinRelationship" in the file
https://svn.apache.org/repos/asf/incubator/tuscany/java/das/rdb/src/test
/resources/companyMappingWithResultDescriptor.xml
Here is what worked for me -
<Command name="testFullOuterJoinRelationship2"
SQL="select * from EMPLOYEE left join DEPARTMENT on
EMPLOYEE.DEPARTMENTID = DEPARTMENT.ID union select * from EMPLOYEE right
join DEPARTMENT on EMPLOYEE.DEPARTMENTID = department.ID where
EMPLOYEE.DEPARTMENTID is null"
kind="Select">
<ResultDescriptor columnName="ID" tableName="EMPLOYEE"
columnType="commonj.sdo.IntObject"/>
<ResultDescriptor columnName="NAME" tableName="EMPLOYEE"
columnType="commonj.sdo.String"/>
<ResultDescriptor columnName="SN" tableName="EMPLOYEE"
columnType="commonj.sdo.String"/>
<ResultDescriptor columnName="MANAGER"
tableName="EMPLOYEE" columnType="commonj.sdo.IntObject"/>
<ResultDescriptor columnName="DEPARTMENTID"
tableName="EMPLOYEE" columnType="commonj.sdo.IntObject"/>
<ResultDescriptor columnName="ID" tableName="DEPARTMENT"
columnType="commonj.sdo.IntObject"/>
<ResultDescriptor columnName="NAME"
tableName="DEPARTMENT" columnType="commonj.sdo.String"/>
<ResultDescriptor columnName="LOCATION"
tableName="DEPARTMENT" columnType="commonj.sdo.String"/>
<ResultDescriptor columnName="DEPNUMBER"
tableName="DEPARTMENT" columnType="commonj.sdo.String"/>
<ResultDescriptor columnName="COMPANYID"
tableName="DEPARTMENT" columnType="commonj.sdo.IntObject"/>
</Command>
Also where can I find more information about ResultDescriptor ?
Thanks again for your help.
-Umesh Tyagi
-----Original Message-----
From: Luciano Resende [mailto:[EMAIL PROTECTED]
Sent: Tuesday, April 24, 2007 8:10 PM
To: [email protected]
Subject: Re: RDB DAS - How to create non containment association ?
Hi Umesh
I have updated the RelationshipTests [1] to cover your scenario. A
Query that retrieves Departments with no employees, and Employees with
no departments and update their relationship.
I hope this helps with your previous concern about supporting this
scenario...
Please let me know if you have any questions,
[1]
https://svn.apache.org/repos/asf/incubator/tuscany/java/das/rdb/src/test
/java/org/apache/tuscany/das/rdb/test/RelationshipTests.java
On 4/24/07, Luciano Resende <[EMAIL PROTECTED]> wrote:
>
> Have you tried simulating a full outer join with a union of left and
> right joins, like below :
>
> select * from DEPARTMENT left join EMPLOYEE on DEPARTMENT.ID =
> EMPLOYEE.DEPARTMENTID UNION select * from DEPARTMENT right join
> EMPLOYEE on DEPARTMENT.ID = EMPLOYEE.DEPARTMENTID WHERE
> employee.DepartmentID IS NULL
>
> If I understood it correct, this would give you all the necessary data
> inside the dataGraph. I quickly tried the query inside the eclipse
> Database Explorer connecting with Derby, and the results looked ok,
> and had the department with no employees, as well as the employees
with no departments.
>
> I'll try to play with this scenario to extend the Relationship
> testcases we have, and if I succeed, I'll send a note with my findings
later on...
>
> On 4/23/07, Kevin Williams <[EMAIL PROTECTED]> wrote:
> >
> > I think I did not explain well.
> >
> > The RDB DAS does not support containment (in the SDO sense)
> > relationships between business dataobjects in a graph. Since all
> > elements must be contained by something, all elements are contained
> > by the (dummy) root of the graph. So, if you read a department
> > along with its related employees then the relationship between
> > department and employees is not containment.
> > Unless I misunderstand, this is what you want.
> >
> > Here is one way to assign an existing employee to an existing
> > department:
> >
> > // Move an employee to dep1 from dep2
> > DataObject emp = (DataObject) dep2.getList("emps").get(0);
> > dep1.getList("emps").add(emp);
> >
> > // Flush changes
> > das.applyChanges(root);
> >
> > If the scenario you have in mind is more complicated than this -
> > like if you want to add employees that are not part of the existing
> > graph
> > - then
> > you are looking at merging graphs. There is some early support for
> > this but not much.
> >
> > --Kevin
> >
> >
> > On 4/23/07, Umesh Tyagi (utyagi) <[EMAIL PROTECTED]> wrote:
> > >
> > > But doesn't it pose a big limitation for DAS RDB ? I mean
> > > associations
> >
> > > are not necessarily containment relations. I want to able to
> > > assign an existing employee to and existing department or a more
> > > intuitive
> > example
> > > would be relationship between "customer service agent" and
"customer".
> >
> > > How am I ever going to achieve that with DAS RDB?
> > >
> > > Thanks
> > > -Umesh Tyagi
> > >
> > > -----Original Message-----
> > > From: Kevin Williams [mailto: [EMAIL PROTECTED]
> > > Sent: Monday, April 23, 2007 3:07 PM
> > > To: [email protected]
> > > Subject: Re: RDB DAS - How to create non containment association ?
> > >
> > > On 4/23/07, Umesh Tyagi (utyagi) <[EMAIL PROTECTED]> wrote:
> > > >
> > > > So whenever I want to associate employees to a department I
> > > > either create a new employee or move employee from some other
department ?
> > >
> > >
> > > That's right.
> > >
> > > I am talking about the case when a "employee" object is currently
> > > > without any associated department. When we want to assign it to
> > > > a department the following query will not include the employee I
> > > > am interested in - "select * from DEPARTMENT left outer join
> > > > EMPLOYEE
> > on
> > > > DEPARTMENT.ID = EMPLOYEE.DEPARTMENTID "
> > > > A right join on the other hand will leave out all the
'departmemt'
> > > > objects without any employee.
> > > >
> > > Thanks
> > > > -Umesh Tyagi
> > > >
> > > >
> > > > -----Original Message-----
> > > > From: Kevin Williams [mailto: [EMAIL PROTECTED]
> > > > Sent: Monday, April 23, 2007 12:43 PM
> > > > To: [email protected]
> > > > Subject: Re: RDB DAS - How to create non containment association
?
> > > >
> > > > If you want departments and their related employees then you
> > > > would typically use a left join rather than a full join. At
> > > > least, this
> > is
> > > > the scenario I see used most often. Our test case:
> > > >
> > > > RelationshipTests.testRelationshipModification2()
> > > >
> > > > demonstrates this.
> > > >
> > > > Thanks,
> > > >
> > > > --Kevin
> > > >
> > > >
> > > >
> > > > To read a set of departments and related employees you would
> > typically
> > >
> > > > use a left outer join rather than a full join since you want
> > > >
> > > > On 4/21/07, Umesh Tyagi (utyagi) < [EMAIL PROTECTED]> wrote:
> > > > >
> > > > > How to create non containment association between two existing
> > > > > objects
> > > > ?
> > > > > For example, lets assume the following relationship is a non
> > > > > containment association i.e. both objects can exist
> > > > > independently
> > of
> > >
> > > > > each other -
> > > > >
> > > > > ------------ ----------
> > > > > |DEPARTMENT| 1______________* |EMPLOYEE|
> > > > > ------------ ----------
> > > > >
> > > > > Playing with samples code I have noticed that in order to
> > > > > create association between two object they need to be part of
> > > > > the same
> > data
> > >
> > > > > graph generated by a single query. So for the following line
> > > > > to
> > work
> > >
> > > > > -
> > > > >
> > > > > department.getList("employees").add(employee)
> > > > >
> > > > > both 'department' and 'employee' dataobjects must be under
> > > > > same
> > root
> > >
> > > > > DataObject instance. To achieve this I tried to do a full
> > > > > outer
> > join
> > >
> > > > > between DEPARTMENT and EMPLOYEE but it is not supported by
> > > > > derby
> > or
> > > > > hsql. The equivalent union result is not typed to DEPARTMENT
> > > > > and EMPLOYEE by DAS. The other option is to set the foreign
> > > > > key value explicitly in the 'employee' object, but it is not
> > > > > desirable. Any other ideas ?
> > > > >
> > > > > -Umesh Tyagi
> > > > >
> > > > >
> > --------------------------------------------------------------------
> > > > > - To unsubscribe, e-mail:
> > > > > [EMAIL PROTECTED]
> > > > > For additional commands, e-mail:
> > > > > [EMAIL PROTECTED]
> > > > >
> > > > >
> > > >
> > > >
> > --------------------------------------------------------------------
> > -
> > > > To unsubscribe, e-mail: [EMAIL PROTECTED]
> > > > For additional commands, e-mail: [EMAIL PROTECTED]
> > > >
> > > >
> > >
> > > ------------------------------------------------------------------
> > > --- To unsubscribe, e-mail: [EMAIL PROTECTED]
> > > For additional commands, e-mail: [EMAIL PROTECTED]
> > >
> > >
> >
>
>
>
> --
> Luciano Resende
> http://people.apache.org/~lresende
> <http://people.apache.org/%7Elresende>
--
Luciano Resende
http://people.apache.org/~lresende
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
--
Luciano Resende
http://people.apache.org/~lresende
