Here's an article on the topic "Deep Entity Handling: Creating and Updating Related Entities" in the context of SAP Gateway:
In the world of SAP Gateway and OData services, Deep Entity Handling is a powerful concept that allows developers to create or update an entity along with its related entities in a single request. This approach is essential in enterprise applications, where business objects are often composed of a main entity and multiple dependent (child) entities.
This article explores the mechanisms of deep entity handling within SAP Gateway, focusing on how to implement, manage, and troubleshoot the creation and update of related entities using OData services.
In OData, a deep insert or deep update refers to an operation where you send a complex JSON payload that includes a main entity and its associated (nested) entities. SAP Gateway interprets this as a single transaction to either:
This avoids multiple round trips between the client and server, ensuring data consistency and atomicity.
Imagine a business scenario where we want to create a Sales Order with multiple Sales Order Items.
{
"SalesOrderID": "1001",
"Customer": "C100",
"OrderItems": [
{
"ItemID": "10",
"Product": "P001",
"Quantity": 5
},
{
"ItemID": "20",
"Product": "P002",
"Quantity": 3
}
]
}
This is a classic deep insert payload where OrderItems is a navigation property of the main SalesOrder entity.
In the Service Builder (SEGW):
SalesOrder and OrderItem.In the Data Provider Extension class (DPC_EXT), override the following method:
METHOD /iwbep/if_mgw_appl_srv_runtime~create_deep_entity.
This method provides access to the entire JSON payload, allowing you to:
METHOD /iwbep/if_mgw_appl_srv_runtime~create_deep_entity.
DATA: ls_sales_order TYPE zcl_sales_mpc=>ts_salesorder,
lt_order_items TYPE STANDARD TABLE OF zcl_sales_mpc=>ts_orderitem.
ls_sales_order = io_data_provider->get_deep_entity( )->get_data( ).
" Create main entity
CALL METHOD zcl_so_handler=>create_sales_order
EXPORTING
is_sales_order = ls_sales_order
IMPORTING
ev_so_id = DATA(lv_so_id).
" Loop and create child entities
LOOP AT ls_sales_order-orderitems INTO DATA(ls_item).
CALL METHOD zcl_so_handler=>create_order_item
EXPORTING
iv_so_id = lv_so_id
is_item = ls_item.
ENDLOOP.
" Return created entity
er_deep_entity = ls_sales_order.
ENDMETHOD.
For deep updates, similar logic applies, but SAP Gateway does not provide a dedicated method like update_deep_entity. You can:
update_entity by manually reading the related entities.Ensure proper transaction management using CALL FUNCTION IN UPDATE TASK or database commits only after all related data is validated. Also:
cx_root exceptions for Gateway to handle HTTP error responses.Deep Entity Handling in SAP Gateway allows for robust, efficient creation and updating of complex business objects. By leveraging SEGW, navigation properties, and careful ABAP implementation, developers can offer seamless integration between SAP systems and external consumers, reducing client-side complexity and improving system performance.