Introduction to CDS Views in SAP ABAP

What is CDS in SAP ABAP?

Core Data Services, or CDS in SAP ABAP, is a set of tools and concepts that SAP has defined as part of the programming model for ABAP on SAP HANA. It allows developers to describe data models, views, and access controls using a declarative SQL-type approach through a language known as ABAP CDS DDL (Data Definition Language).

In contrast to the classic models which rely on ABAP Data Dictionary (SE11 data tables and views) compatible views, CDS views use DDL source code to define views which are designed to be executed on a database engine that has been optimized for SAP HANA.

Why CDS was Implemented

Prior to CDS, all custom business logic and data transformations were done in ABAP application code, causing a major performance bottleneck. CDS moves this logic closer to the database, enabling the use of HANA's in-memory computing for significant performance gain.

Some of the benefits of using CDS with SAP ABAP are:

• Performance: Moves data-related logic to the database
• Reusability: CDS views can be consumed by different applications
• Semantic enrichment: Annotations provide metadata for OData, UI, and analytics
• Integration: Works effortlessly with OData, Fiori, BW/BEx queries
• Standardization: Part of the SAP ABAP RESTful Application Programming Model (RAP)

What Is a CDS View in SAP ABAP?

A CDS view in SAP ABAP is a virtual data model constructed using ABAP CDS DDL syntax. It is layered on top of database tables or other CDS views, and merges and transforms data through SQL-like constructs. Activation of a CDS view creates a SQL view in the SAP HANA database.

Different Kinds of CDS Views

You should be aware of the following CDS entity types:

Type	Description
Basic Interface View	Direct access to the database table; basic representation of raw data
Composite Interface View	Integrates multiple basic views or other composite views
Consumption View	Optimized for a particular application or UI use case
Projection View	Used in RAP; limits the fields consumer can access
Value Help View	Provides search help (F4 values) for UI elements

CDS Views in SAP ABAP on HANA

The integration of CDS views in SAP ABAP on HANA with SAP HANA's in-memory database engine provides the most benefit. Each time a CDS view is created, SAP HANA processes it as a Native SQL View. This means all the joins, aggregations, filters, and calculations happen in-memory for a super-fast response time.

HANA Innovations CDS Views Benefit From

• Code-to-data: Computation is done inside HANA instead of data processing being brought into ABAP
• CDS analytic capabilities: @Analytics annotations allow for analytics queries
• Better execution plans: HANA's larger optimizer benefits from the structure of CDS views in SAP ABAP on HANA
• Less data transfer: Only the expected filtered and aggregated results are passed to the application server

For all the above reasons, CDS views are the basis for the RAP (RESTful ABAP Programming) model, Embedded Analytics, OData services, and SAP Fiori apps.

How to Create a CDS View in SAP ABAP

To be able to create a CDS view, you will need the SAP ABAP Development Tools (ADT). Here is a guide that will show you how to create a CDS view from the beginning to the end.

Prerequisites

• SAP HANA-Based System (e.g. SAP S/4 HANA)
• Eclipse SDK with SAP ABAP Development Tools (ADT) Plugin
• SAP System Development Authorization

Step 1: Create a New ABAP Project in Eclipse

To be able to create a CDS view, you must be able to navigate to your ABAP Project. Also, you need to be able to connect to your ABAP system. Note that CDS views also cannot be developed/created in SE80.

Step 2: Create a New CDS Data Definition

To create a new CDS Data Definition:

• Right click on the desired package in the Project Explorer
• Select New > Other ABAP Repository Object
• Select Core Data Services -> Data Definition
• Then, click Next

Step 3: Input the Details of the CDS View

When you fill the form, here are the things that you must input:

• Name — use something like ZI_SalesOrder (follow the SAP Standard Naming convention. Always use Z or Y to mark anything custom)
• Description — input Sales Order CDS View for example
• Referenced Object — input the database table that will be the base for this view, for example VBAK

After that, click on Next. Then select the transport request and then finish.

Step 4: Write the DDL Source Code

When Eclipse launches the DDL editor, it offers a default template. Take a look at this example for a simple CDS view in SAP ABAP:

@AbapCatalog.viewEnhancementCategory: [#NONE]

@AccessControl.authorizationCheck: #CHECK

@EndUserText.label: 'Sales Order Basic View'

@Metadata.ignorePropagatedAnnotations: true

define view entity ZI_SalesOrder

  as select from vbak

{

  key vbeln        as SalesOrder,

      erdat        as CreationDate,

      auart        as OrderType,

      kunnr        as SoldToParty,

      netwr        as NetValue,

      waerk        as Currency

}

Key elements explained:

• @AbapCatalog.viewEnhancementCategory: How the view can be enhanced
• @AccessControl.authorizationCheck: #CHECK: Provides access control via DCL
• @EndUserText.label: A user-friendly label for the view
• define view entity: Defines the CDS view entity (modern RAP syntax)
• as select from vbak: From the VBAK database table the selection is made
• Aliases (like vbeln as SalesOrder) let you name fields better

Step 5: Add Associations (Joins)

CDS views allow associations, a means for defining lazy-loaded joins:

define view entity ZI_SalesOrder

  as select from vbak

  association [0..1] to vbap as _Items

    on $projection.SalesOrder = _Items.vbeln

{

  key vbeln        as SalesOrder,

      erdat        as CreationDate,

      kunnr        as SoldToParty,

      /* Association */

      _Items

}

Because associations are only resolved on explicit consumption, they promote better performance.

Step 6: Activate the CDS View

Hit Ctrl + F3 or click the Activate button. Once activated successfully, a view will be generated in the HANA database, and a corresponding SQL view will be created in the SAP backend.

Step 7: CDS View Testing

In ADT, you can use the Data Preview (F8) option to see the data, or you can access the view from an ABAP program:

SELECT * FROM zi_salesorder INTO TABLE @DATA(lt_orders).

CDS views can be accessed the same way as ABAP dictionary views using standard Open SQL.

SAP ABAP CDS Annotations

SAP ABAP CDS annotations, which are denoted by an '@' symbol, are used to add additional semantics to the CDS views and can be used by multiple SAP frameworks to automatically create OData services, Fiori UI components, analytics and other capabilities without any additional coding.

Significant CDS Annotations

1. @AbapCatalog Annotations

Control how the view is processed in the ABAP catalog:

@AbapCatalog.viewEnhancementCategory: [#NONE]

@AbapCatalog.sqlViewName: 'ZSALESORDER'

2. @AccessControl Annotations

Control authorization checks:

@AccessControl.authorizationCheck: #CHECK

3. @EndUserText Annotations

Provide labels and descriptions for user interfaces:

@EndUserText.label: 'Sales Order'

@EndUserText.quickInfo: 'Displays sales order header data'

4. @Analytics Annotations

Make the view available for embedded analytics and BW extraction:

@Analytics.dataCategory: #CUBE

@Analytics.dataExtraction.enabled: true

5. @OData Annotations

Allow automatic generation of OData services:

@OData.entitySet.name: 'SalesOrders'

@OData.publish: true

6. @UI Annotations

Control the rendering of the Fiori user interface, including list items, headers, and facets:

@UI.lineItem: [{ position: 10, label: 'Sales Order' }]

@UI.selectionField: [{ position: 10 }]
@UI.headerInfo.typeName: 'Sales Order'

7. @VDM (Virtual Data Model) Annotations

Categorize views in the SAP VDM hierarchy:

@VDM.viewType: #BASIC

SAP ABAP CDS annotations are what make views "smart" — basically, they convert raw SQL views into rich, user-friendly, and semantically correct data services.

CDS Functions in SAP ABAP

CDS functions in SAP ABAP are SQL functions that are built in for use within the CDS DDL for transforming and calculating field values. They are akin to SQL functions but are defined inside the CDS ecosystem.

CDS Functions Classification

1. Functions of Numeric Data Types

abs(amount)          -- Absolute value

ceil(price)          -- Ceiling
floor(price)         -- Floor
div(a, b)            -- Integer division
mod(a, b)            -- Modulo

2. Functions of String Data Types

concat(firstname, lastname)         -- Concatenation of strings

left(name, 5)                       -- Left substring of length 5
right(name, 3)                      -- Right substring of length 3
length(description)                 -- Length of string
upper(name)                         -- Convert string to uppercase
lower(email)                        -- Convert string to lowercase
ltrim(name)                         -- Left trim whitespace
rtrim(name)                         -- Right trim whitespace
replace(name, 'old', 'new')         -- Replace part of string with new substring

3. Functions of Date Data Types

dats_days_between(date1, date2)     -- Number of days between two dates

dats_add_days(date, 30)             -- Add 30 days to date
dats_is_valid(date)                 -- Validate date
tstmp_to_dats(timestamp, ...)       -- Convert timestamp to date

4. Functions of Type Conversion

cast(amount as abap.dec(15,2))      -- Conversion to specific type

5. Functions of Conditional Logic

case status

  when 'A' then 'Active'
  when 'I' then 'Inactive'
  else 'Unknown'
end as StatusText

6. Functions of Aggregation

Usage in CDS views in SAP ABAP with GROUP BY:

sum(netvalue)    as TotalNetValue,

count(*)         as OrderCount,
avg(netvalue)    as AvgNetValue,
max(netvalue)    as MaxNetValue,
min(netvalue)    as MinNetValue

7. Functions of Currency and Unit Conversion

currency_conversion(

  amount => amount,
  source_currency => currency,
  target_currency => 'USD',
  exchange_rate_date => $session.system_date
) as AmountInUSD

These built-in CDS functions in SAP ABAP eliminate the need for ABAP post-processing and concentrate all computation in the HANA layer.

CDS Views Recommendations

To achieve maximum effectiveness in your CDS views in SAP ABAP, apply the following recommendations:

• VDM layering: Use basic, composite, and consumption views
• Use good aliases: Change technical field names to more user-friendly names as needed
• Access control: Use @AccessControl.authorizationCheck: #CHECK in productive systems
• Join optimization: Opt to use associations instead of joins
• Annotation coverage: Use @EndUserText, @UI, and @VDM annotations for coverage
• CDS View Reusability: Use existing CDS views instead of creating new ones
• Data Preview Testing: Use the Data Preview in ADT (F8) to test CDS output
• RAP Projection Views: Use projection views to expose data through the RAP model

Career Prospects with CDS in SAP ABAP

Having expertise in CDS views in SAP ABAP gives you a multitude of options in your career:

• SAP ABAP Developer (S/4HANA) — Developing with ABAP and S/4HANA requires use of CDS
• SAP Fiori Developer — Developing Fiori requires an understanding of CDS and OData
• SAP BTP Developer — Developing for BTP is almost exclusively done with CDS and RAP
• SAP Analytics Developer — Developing for Embedded Analytics and BW relies on CDS
• SAP Technical Architect — Building data models for HANA requires knowledge of CDS

With expertise in SAP ABAP development with CDS, developers in India can expect to earn ₹8–25 LPA, while those in the US can earn $90,000–$140,000 based on their expertise and knowledge.

Conclusion

The potential of CDS in SAP ABAP is unrivaled in SAP development. CDS views streamline the entire process of constructing SAP Fiori Apps, OData services, and embedded analytics. They go as far as creating virtual data models.

We focused on the following in this CDS view in SAP ABAP tutorial:

• The definition of CDS in SAP ABAP and the reasons behind its conception
• The workings of CDS views and SAP HANA
• How to create CDS views in SAP ABAP articulated in clear steps
• The practical usage of SAP ABAP CDS annotations
• The transforming data capabilities of CDS functions in SAP ABAP
• Career advice and best practices

Furthering your knowledge of SAP ABAP development is going to require enrolling in a formal course on CDS views, RAP, and Fiori development. These subjects are integrated into SAP ABAP on HANA. Start with the easier modules, then move on to constructing CDS views in a sandbox system, and finally to creating OData services and Fiori applications.

Our experts have designed online courses in SAP ABAP, Fiori Development, RAP, and CDS Views to provide learners with the skills that the industry needs. Start your SAP ABAP journey with us today.