Logical Data Service

Question

Hi all,
I´m trying to create a phsysical data service that uses two physical data services (one Store procuredure and one table).
I what two create a join clause between my strore procedure and my table, but i got this error message:
+"cannot create relationship from/to any Data service other than entity data service.+
+One or both of the data services chosen are not and entity Data SErvice"+
What I need to do is:
I have A AND B values as input to my logical data service.
I need to use A and B value to get another value C in my physical data service( type: Relational Table).
C will be physical data service (type Store Procedure) input data. The return of this procedure will be mapped in (XSD) file that represents my entity.
Does anybody can help me?

Answer 1

If I understand correctly, your need to satisfy conditions on parameters A and B with your table, so you can extract C as a result from the table and use it as a parameter in your stored procedure to return the result of the stored procedure.
In XQuery this kind of join looks loosely like this:
for $t in ns1:TABLE()
where $t/column1 eq $A
where $t/column2 eq $B
return
for $s in ns2:STOREDPROC($t/C)
return
<myresulttype>
<field1>{fn:data($s/column1)}</field1>
</myresulttype>
The error message you have indicates that you are trying to create a relationship function. While it is possible to express joins through relationships, you can also do joins using the Query Map editor.
The chapter "[Create Your First Data Services|http://download.oracle.com/docs/cd/E13162_01/odsi/docs10gr3/datasrvc/Create%20Your%20First%20Data%20Services.html#CreateYourFirstDataServices-CreatingaLogicalDataService]" describes how to create a join graphically using the Query Map. The only difference in your case is that you would map your join line (Explained in "Setting up a Join Condition" in the docs) would be mapped to the parameter of the stored procedure.
Edited by: alexkotopoulis on Jan 16, 2009 1:56 PM
Edited by: alexkotopoulis on Jan 16, 2009 1:57 PM