Getting Started with SAP ABAP Core Data Services (CDS)

Learn how to use SAP ABAP Core Data Services (CDS) with detailed step-by-step explanations and examples. Improve your SAP ABAP development skills with this comprehensive guide on CDS.

Emre Göçmen

Table of Contents

  1. What is CDS?
  2. Advantages of ABAP CDS
  3. Creating CDS Views
  4. CDS Associations
  5. Creating OData Service with CDS
  6. Conclusion

1. What is CDS?

Core Data Services (CDS) is a framework used for data modeling and data access. CDS allows us to perform complex queries and operations at the database level in a simpler and more performant way. ABAP CDS integrates this concept with the ABAP language, enabling us to optimize data access and processing workflows.

2. Advantages of ABAP CDS

  • Performance Improvement: Since it operates at the database level, data operations are faster.
  • Reusability: Defined CDS views can be used in different applications.
  • Central Data Model: Provides ease of maintenance and management.
  • Rich Annotation Support: You can add additional information for UI, OData services, and more.

3. Creating CDS Views

3.1 Basic CDS View

Step 1: Open a project with Eclipse or ABAP Development Tools (ADT).

Step 2: Create a new CDS view.

  • Right-click on the project > New > ABAP Repository Object > Core Data Services > Data Definition

Step 3: Name your CDS view and add the following code.

@AbapCatalog.sqlViewName: 'ZCUSTVIEW'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #NOT_REQUIRED
@EndUserText.label: 'Customer Basic Data'
define view Z_Customer_View
  as select from kna1 {
    key kunnr as CustomerNumber,
    name1 as Name,
    land1 as Country,
    ort01 as City,
    pstlz as PostalCode
  }

Description:

  • @AbapCatalog.sqlViewName: Specifies the name of the physical view to be created in the database.
  • @AccessControl.authorizationCheck: Sets the authorization check.
  • @EndUserText.label: Adds a description for the view.
  • define view: Defines the CDS view.
  • select from kna1: Selects data from the KNA1 (Customer Master) table.

3.2 Using Annotations

Annotations allow us to add additional information to CDS views and are used for various purposes.

Example: Adding UI Annotations

@AbapCatalog.sqlViewName: 'ZCUSTVIEW'
@AccessControl.authorizationCheck: #NOT_REQUIRED
@EndUserText.label: 'Customer Basic Data'
@UI.headerInfo: { typeName: 'Customer', typeNamePlural: 'Customers' }
define view Z_Customer_View
  as select from kna1 {
    key kunnr as CustomerNumber,
    @UI.selectionField: [{ position: 10 }]
    @UI.lineItem: [{ position: 10 }]
    name1 as Name,
    land1 as Country,
    ort01 as City,
    pstlz as PostalCode
  }

Description:

  • @UI.headerInfo: Sets the header information to be displayed in the UI.
  • @UI.selectionField and @UI.lineItem: Determines the ordering and visibility of fields in the user interface.

4. CDS Associations

Associations allow us to establish relationships between CDS views and simplify JOIN operations.

Example: Combining Customer and Order Data

@AbapCatalog.sqlViewName: 'ZCUSTORDVIEW'
@AccessControl.authorizationCheck: #NOT_REQUIRED
@EndUserText.label: 'Customer Orders'
define view Z_Customer_Order_View
  as select from Z_Customer_View as Customer
  association [0..*] to vbak as _Orders on $projection.CustomerNumber = _Orders.kunnr
{
    key Customer.CustomerNumber,
    Customer.Name,
    Customer.Country,
    _Orders
}

Description:

  • association [0..*]: Establishes a relationship with multiple orders.
  • _Orders: Alias representing the association.

Accessing Associated Data

Instead of using LEFT OUTER JOIN, you can directly use the association to access related data.

define view Z_Customer_Order_Detail_View
  as select from Z_Customer_Order_View
  association [0..*] to vbap as _OrderItems on _Orders.vbeln = _OrderItems.vbeln
{
    key CustomerNumber,
    Name,
    _Orders.vbeln as OrderNumber,
    _OrderItems.posnr as ItemPosition,
    _OrderItems.matnr as MaterialNumber,
    _OrderItems.kwmeng as OrderQuantity
}

5. Creating OData Service with CDS

You can publish CDS views as OData services.

Step 1: Add OData Annotation to the CDS View

@AbapCatalog.sqlViewName: 'ZCUSTODATA'
@AccessControl.authorizationCheck: #NOT_REQUIRED
@EndUserText.label: 'Customer Data OData Service'
@OData.publish: true
define view Z_Customer_OData
  as select from kna1 {
    key kunnr as CustomerNumber,
    name1 as Name,
    land1 as Country,
    ort01 as City,
    pstlz as PostalCode
  }

Step 2: Activate the OData Service

  • Without needing to use transaction SEGW, the service is automatically created.
  • Use transaction /IWFND/MAINT_SERVICE to activate the service.

Step 3: Testing the Service

  • Open the following URL in your web browser: 
    https://<server_address>:<port>/sap/opu/odata/sap/ZCUSTODATA_CDS/

6. Conclusion

ABAP CDS allows you to manage data modeling and data access in SAP systems in a modern and efficient way. With CDS, you can write high-performance, low-maintenance, and reusable code. Features like annotations and associations enable you to enrich your data models and simplify your integrations with OData services.