Remote Persistency And Entity Services References

Question

Hi Guys,
I try to build a composite service with remote persistency (via webservices). There are several tuturials explainig it:
81 Using a Web Service as External Service
85 Using RFCs as External Services
95 Implementing Remote Persistency with CAF and RFCs
This is no problem at all, when only using one entity service or several entity service with no relations to each other. But for an demo application I try to create two entity services ("Main" and "Sub") and the "Main" entity service should have a relation to "Sub".
What I try:
1.) Create the entity services "main" with an own id.
2.) Create the entity services "sub" with an own id.
3.) Open the attributs for main again and create an relation to the entity service sub (via add button).
4.) deactivate "local persistency" for every entity service
5.) create the mapping for the read and find by operations.
But how can I "teach" my application the relation between these entity services? A look into the sql database shows an empty relation table and the pattern "relation tab" is empty, too.
I try to create a findby operation for the entity service "sub" like "findByMainID". But the attribut list only shows attributs of the "sub" entity service.
Are entity service relations working with remote persistency?
Kind regards
Martin

Answer 1

Hi Austin,
thank you for you answer. But the findBy operation is only one problem. The main problem is the missing option to map a webservice to a reference/relationship. Due this fact the application has no chance to know which child record is part of which main record or which main record is parent of which child record. As a result I have two totaly isolated entity services which doesnt know, that they relate to each other. The application has no information about the relationship.
When I create only one entity service with a complex attribute for child attributs I didn't have the these problem. I could map parameters to the (parent) attributs of the entity service and the (child) attributs of the complex attributes in the same step. In this way the application have informations about the relationship between parent and child records. For example a web service for the read operation could return exactly one record for the attributs of the parent entity service and a list of records to the child attributes (modelled as complex attributs) in case of a 0...n cardinality. I think there must be a solution like this for two entity services with a relationship between each other.
Do you understand my problem? Maybe I've missunderstood something. But what?
Thank you
Martin