Sap Abap Cds

SAP ABAP CDS (Core Data Services)

Related Skills

• sap-abap: Use for ABAP programming patterns used with CDS or when implementing EML statements in ABAP
• sap-btp-cloud-platform: Use for CDS deployment scenarios on BTP or ABAP Environment configurations
• sap-fiori-tools: Use when building Fiori Elements applications that consume CDS views or working with UI annotations
• sap-cap-capire: Use for comparing CDS syntax between ABAP and CAP or when integrating ABAP CDS with CAP services
• sap-api-style: Use when documenting CDS-based OData services or following API documentation standards

When to Use This Skill

Use this skill when creating ABAP CDS views or view entities, defining associations and cardinalities, adding UI or semantic annotations, implementing DCL access control, handling currency/unit fields, troubleshooting CDS compiler errors, or comparing classic CDS views with newer view entities.

Quick Reference: https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/abencds.html | SAP Cheat Sheets: https://github.com/SAP-samples/abap-cheat-sheets/blob/main/15_CDS_View_Entities.md

Version Compatibility

This skill covers CDS features from 7.40 SP8 through ABAP Cloud. Key version boundaries:

On a 7.40 system: Use DEFINE VIEW (not DEFINE VIEW ENTITY). CDS table functions are not available before 7.50. Basic DCL (DEFINE ROLE with pfcg_auth) is available from 7.40 SP08, but implicit role evaluation in ABAP SQL requires 7.50+. $session.user/client/system_language are available from 7.40 SP08. The templates in templates/ include both classic CDS View and View Entity variants.

Table of Contents

• 1. CDS View Fundamentals
• 2. Essential Annotations
• 3. Expressions and Operations
• 4. Built-in Functions
• 5. Joins
• 6. Associations
• 7. Input Parameters
• 8. Aggregate Expressions
• 9. Access Control (DCL)
• 10. Data Retrieval from ABAP
• 11. Common Errors and Solutions
• 12. Useful Transactions and Tables
• Bundled Resources
• Source Documentation

1. CDS View Fundamentals

View Types

Recommendation: Use CDS View Entities for new development.

Basic CDS View Syntax

@AbapCatalog.sqlViewName: 'ZCDS_EXAMPLE_V'
@AbapCatalog.compiler.CompareFilter: true
@AccessControl.authorizationCheck: #NOT_REQUIRED
@EndUserText.label: 'Example CDS View'

define view ZCDS_EXAMPLE
  as select from db_table as t
{
  key t.field1,
      t.field2,
      t.field3 as AliasName
}

CDS View Entity Syntax (7.55+)

@AccessControl.authorizationCheck: #NOT_REQUIRED
@EndUserText.label: 'Example View Entity'

define view entity Z_CDS_EXAMPLE
  as select from db_table as t
{
  key t.field1,
      t.field2,
      t.field3 as AliasName
}

Key Difference: View entities omit @AbapCatalog.sqlViewName - no SQL view generated.

Eclipse ADT Setup

1. File → New → Other → Core Data Services → Data Definition
2. Enter name, description, and package
3. Select template (view, view entity, etc.)

2. Essential Annotations

Core Annotations

Essential annotations for CDS development:

• @AbapCatalog.sqlViewName - SQL view name (max 16 chars)
• @AbapCatalog.compiler.CompareFilter - Optimize WHERE clauses
• @AccessControl.authorizationCheck - Set to #NOT_REQUIRED, #CHECK, #MANDATORY, or #NOT_ALLOWED
• @EndUserText.label - User-facing description
• @Metadata.allowExtensions - Allow view extensions

Complete Reference: See references/annotations-reference.md for 50+ annotations with examples.

Semantics Annotations (Currency/Quantity)

Required for CURR and QUAN data types to avoid error SD_CDS_ENTITY105:

-- Currency fields
@Semantics.currencyCode: true
waers,
@Semantics.amount.currencyCode: 'waers'
amount,

-- Quantity fields
@Semantics.unitOfMeasure: true
meins,
@Semantics.quantity.unitOfMeasure: 'meins'
quantity

UI Annotations (Fiori Elements)

@UI.lineItem: [{ position: 10 }]
@UI.identification: [{ position: 10 }]
@UI.selectionField: [{ position: 10 }]
field1,

@UI.hidden: true
internal_field

Consumption Annotations (Value Help)

@Consumption.valueHelpDefinition: [{
  entity: { name: 'I_Currency', element: 'Currency' }
}]
waers

For complete annotation reference, see references/annotations-reference.md.

3. Expressions and Operations

CASE Expressions

Simple CASE (single variable comparison):

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

Searched CASE (multiple conditions):

case
  when amount > 1000 then 'High'
  when amount > 100 then 'Medium'
  else 'Low'
end as AmountCategory

Comparison Operators

Standard operators: =, <>, <, >, <=, >= Special operators: BETWEEN x AND y, LIKE, IS NULL, IS NOT NULL

Complete Reference: See references/expressions-reference.md for all operators and expressions.

Arithmetic Operations

quantity * price as TotalAmount,
amount / 100 as Percentage,
-amount as NegatedAmount

Session Variables

Available system variables (SY fields equivalent):

• $session.user (SY-UNAME) - Current user [7.40 SP08+]
• $session.client (SY-MANDT) - Client [7.40 SP08+]
• $session.system_language (SY-LANGU) - Language [7.40 SP08+]
• $session.system_date (SY-DATUM) - Current date [7.51+]

Note: $session.user/client/system_language are available from 7.40 SP08. $session.system_date requires 7.51+. @Environment.systemField requires 7.50+.

Complete Reference: See references/expressions-reference.md for all system variables.

$session.user as CurrentUser,
$session.system_date as Today

4. Built-in Functions

CDS provides comprehensive built-in functions for string, numeric, and date operations.

Key Function Categories

• String Functions: concat(), length(), substring(), upper(), lower(), replace()
• Numeric Functions: abs(), ceil(), floor(), round(), division()
• Date Functions: dats_add_days(), dats_add_months(), dats_days_between()
• CAST Expression: Convert between ABAP data types

Note: upper() and lower() in CDS require 7.51+. On 7.40/7.50, case conversion must be performed in ABAP after selecting (there is no CDS equivalent).