Hello Adriano,
To return a graph of related elements, the RDB DAS depends on the user
providing a Query that expresses the relationship between the elements.
This is most often done by providing a query that includes a join. See
the "relationship" examples in the DAS test suite.
Thanks,
--Kevin
Adriano Crestani wrote:
Another doubt:
I have the following tables on my database:
create table B (
ID INTEGER NOT NULL PRIMARY KEY
);
create table A (
ID INTEGER NOT NULL PRIMARY KEY,
B_ID INTEGER,
FOREIGN KEY (B_ID) REFERENCES B(ID)
);
OK, then I was analyzing the generated sdo graph when I execute the query
"select * from A, B;", I got something like this:
Graph1:
http://cwiki.apache.org/confluence/download/attachments/45093/das_graph.JPG
I understand the column B_ID would be considered only an integer
column when
of table A when there is no B table returned on the query. However, the B
table is also returned on the query and as the B_ID column is a FK to the
table B, shouldn't the graph be like this?:
Graph2:
http://cwiki.apache.org/confluence/download/attachments/45093/das+graph+as+I+suppose+it+shoud+be.JPG
This way I think the data returned by the query would be better
represented
on the graph. Maybe there is a reason for the graph to be generated as
Graph1 instead of Graph2.
What do you say guys?
Adriano Crestani
On 4/5/07, Adriano Crestani <[EMAIL PROTECTED]> wrote:
Thanks kelvin ; )
Adriano Crestani
On 4/4/07, Kevin Williams <[EMAIL PROTECTED]> wrote:
>
> The RDB DAS will only populate a graph with data returned from the
used
> query. If you want a graph that contains data from related tables
then
> the query provided must return that data (typically a join). The
> relationship tests in the test suite demonstrate this.
> --Kevin
>
> Adriano Crestani wrote:
>
> > Let me try to explain my doubt:
> >
> > Lets suppose I create a select command and execute it. The returned
> > ResultSet has an attribute that belongs to the table X and is a
FK to
> the
> > table Y, but no Y attribute is contained in the ResultSet. The
> > question is:
> > does the das create, and also populate, the SDO graph only with the
> > metadata
> > and data contained in the ResultSet or the das also adds to the SDO
> graph
> > the referenced Y table and its attributes and keep doing it till
there
> > is no
> > more referenced table?
> >
> > I expect to be clear enough ; )
> >
> >
> > Adriano Crestani
> >
>
>
>
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