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];
table.primaryKey.pkcolumns = ["KnowingCustomerID","KnownCustomerID"];
Relationships that are stored in association tables such as knows can be similarly defined as simple associations.
Use the keyword over to specify the additional table and any required columns.
Service definition: sample.odata:assoccomplex.xsodata
service {
"sample.odata:customer.hdbtable" as "Customers";
"sample.odata:order.hdbtable" as "Orders";
association "Customer_Orders"
principal "Customers"("ID") multiplicity "*"
dependent "Customers"("ID") multiplicity "*"
over "sample.odata:knows.hdbtable" principal ("KnowingCustomerID")
dependent ("KnownCustomerID");
}
With the keywords principal and dependent after over you can specify which columns from the
association table are joined with the principal respectively dependent columns of the related entities. The
number of columns must be equal in pairs, and their order in the list is important.
The generated Association in the metadata document is similar to the one created for a simple association
except that the ReferentialConstraint is missing:
tp://localhost:8002/sample/odata/assoccomplex.xsodata/$metadata
Navigation Properties
By only defining an association, it is not possible to navigate from one entity to another. Associations need to be
bound to entities by an NavigationProperty. You can create them by using the keyword navigates:
Service definition: sample.odata:assocnav.xsodata
service {
"sample.odata:customer.hdbtable" as "Customers" navigates
("Customer_Orders" as "HisOrders");
"sample.odata:order.hdbtable" as "Orders";
association "Customer_Orders" principal "Customers"("ID") multiplicity
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P U B L I C
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SAP HANA Developer Guide
Defining Web-based Data Access