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intro

title: 'Tutorial: Creating an OData Service with SAP Gateway Builder' description: 'A step-by-step guide to creating and activating an OData service in an SAP ecosystem using the Gateway Builder (SEGW).'​

Overview​

This guide provides a comprehensive walkthrough for creating a functional OData service within the SAP Gateway Hub Framework[1]. The objective is to expose data from the SAP Business Suite (e.g., ERP, CRM) as an HTTP/REST API[1]. We will use the SAP Gateway Service Builder (Transaction SEGW) to model, create, implement, and activate the service.

The process involves defining a data model, generating runtime objects, implementing the data provider logic, and finally, registering the service for consumption[1].

Prerequisites​

Before you begin, ensure you have the following:

  • Access to an SAP Gateway system.
  • The necessary developer authorizations for transactions SEGW, SE80, and /IWFND/MAINT_SERVICE.
  • A clear understanding of the backend data source you want to expose (e.g., a BAPI, RFC, or DDIC table/view)[1].
  • An existing package for development objects or authorization to create a new one.

Step 1: Create a New Project​

The first step is to create a project in the SAP Gateway Builder, which will serve as a container for your OData service development objects.

  1. Launch the SAP Gateway Service Builder using transaction code SEGW.
  2. Click the Create Project button.
  3. In the "Create Project" dialog box, provide the following details:
    • Project: A unique name for your project (e.g., ZDEMO_SALES_ORDER).
    • Description: A short, meaningful description.
    • Package: Assign a package (e.g., $TMP for a local object or a transportable package).
  4. Click Save. Your project structure will be created with several folders, including Data Model, Service Implementation, Runtime Artifacts, and Service Maintenance.

Step 2: Define the Data Model​

The data model defines the structure of your OData service, including entities, properties, and relationships. This corresponds to the "Data Model" step in your architecture diagram[1].

Create an Entity Type

An Entity Type represents a single data object, similar to a structure in ABAP.

  1. In your project, right-click on the Data Model folder and select Create > Entity Type.
  2. In the wizard, select Create Entity Type and provide a name (e.g., SalesOrder).
  3. Check the Create Related Entity Set checkbox to automatically create the corresponding collection.
  4. Click Continue.

Define Properties

Now, add properties (fields) to your Entity Type.

  1. Expand the SalesOrder Entity Type and double-click on the Properties folder.
  2. Click the Append Row button to add fields. For each property, define:
    • Name: The property name (e.g., SalesOrderID, CustomerName, OrderDate).
    • Is Key: Check this box for the property that uniquely identifies an entity (e.g., SalesOrderID).
    • Type: The Edm Core Type (e.g., Edm.String, Edm.DateTime).
    • ABAP Field Name: The corresponding field name in the backend ABAP structure.
    • Other attributes as needed (e.g., Max Length, Precision, Nullable).
  3. Save your changes.

Step 3: Generate Runtime Objects​

Once the data model is defined, you generate the runtime artifacts. These are the ABAP classes that form the technical foundation of your service[1].

  1. Click the Generate Runtime Objects button (looks like a magic wand) in the application toolbar.
  2. A dialog box will appear, proposing names for the Data Provider Class (DPC) and Model Provider Class (MPC) extensions, along with the technical service name. It's recommended to keep the default names.
  3. Confirm the details and click Continue.
  4. Assign the generated objects to your package when prompted.
  5. After generation, you will see green status lights next to the generated classes in the Runtime Artifacts folder.

Step 4: Implement the Service Logic​

This is where you write the ABAP code to handle CRUD-Q (Create, Read, Update, Delete, Query) operations. The logic will reside in the Data Provider Class extension (_DPC_EXT).

  1. Expand the Service Implementation folder and find your Entity Set (e.g., SalesOrderSet).
  2. Right-click on GetEntitySet (Query) and select Go to ABAP Workbench.
  3. You will be taken to the _DPC_EXT class. Place your cursor on the SALESORDERSET_GET_ENTITYSET method and click the Redefine button.
  4. Implement your data retrieval logic here. This is where you would call a BAPI, RFC, or use a SELECT statement to fetch data from the SAP Business Suite (ERP, CRM, etc.)[1].
* Sample implementation for the GET_ENTITYSET method

DATA: lt_sales_orders TYPE STANDARD TABLE OF BAPI_SALES_ORDER_S, "Example BAPI structure
      ls_sales_order  LIKE LINE OF lt_sales_orders,
      ls_entity       LIKE LINE OF et_entityset.

* Call a BAPI or perform a SELECT to fetch data
SELECT * FROM vbak INTO TABLE @DATA(lt_vbak) UP TO 50 ROWS.

* Map the retrieved SAP data to the OData entity structure
et_entityset = CORRESPONDING #( lt_vbak ).

  1. Activate the redefined method and the entire class. Repeat this process for other methods you need to implement (e.g., GET_ENTITY for reading a single record).

Step 5: Register and Activate the Service​

Your service is now built but needs to be registered and activated in the SAP Gateway Hub to become accessible.

  1. In your project, expand the Service Maintenance folder.
  2. Select your Gateway system alias (e.g., LOCAL).
  3. Click the Register button.
  4. In the "Add Service" dialog, ensure the correct system alias is selected and assign your service to a package (or select Local Object). Click Continue.
  5. A success message will confirm the registration. The status light should turn green.
  6. If the service is not active by default, use transaction /IWFND/MAINT_SERVICE. Find your service in the list, select it, and click Activate ICF Node if it's not already active.

Step 6: Test the OData Service​

Finally, test your service to ensure it's working correctly.

  1. In transaction /IWFND/MAINT_SERVICE, select your service.
  2. Click the SAP Gateway Client button.
  3. The client will open with the base service URL.
  4. To test, execute the following URIs:
    • Check metadata: /sap/opu/odata/sap/ZDEMO_SALES_ORDER_SRV/$metadata
    • Query the Entity Set: /sap/opu/odata/sap/ZDEMO_SALES_ORDER_SRV/SalesOrderSet
    • Query with JSON format: /sap/opu/odata/sap/ZDEMO_SALES_ORDER_SRV/SalesOrderSet?$format=json
  5. A successful test will return an HTTP status code of 200 and the corresponding data in the response body. Your OData service is now a live HTTP/REST API[1].