CDS Views | Technical Training — David Ollero Montes

Interface View: technical access

The Interface layer (ZI_ prefix) models access to the database table and its associations, without UI annotations. It's the reusable layer consumed by any client.

ABAP CDSZI_CONTRACT_MANAGER.ddls

@AbapCatalog.sqlViewName: 'ZIVCONTRMGR'
@AccessControl.authorizationCheck: #CHECK
define root view entity ZI_CONTRACT_MANAGER
  as select from zcontract
{
  key contract_id  as ContractId,
      manager_1    as ContractManager1,
      manager_2    as ContractManager2,
      status       as Status,
      last_changed as LocalLastChangedAt,

      // association to the business partner entity
      association [0..1] to I_BusinessPartner as _Manager
        on $projection.ContractManager1 = _Manager.BusinessPartner
}

Consumption View: the exposed layer

The Consumption layer (ZC_ prefix) adds the @UI annotations that Fiori Elements needs to automatically generate lists, columns and filter fields — without writing an XML view by hand.

ABAP CDSZC_CONTRACT_MANAGER.ddls

@Metadata.allowExtensions: true
@UI.headerInfo: { typeName: 'Contract', typeNamePlural: 'Contracts' }
define root view entity ZC_CONTRACT_MANAGER
  as projection on ZI_CONTRACT_MANAGER
{
  @UI.lineItem: [{ position: 10, importance: #HIGH }]
  @UI.selectionField: [{ position: 10 }]
  key ContractId,

  @UI.lineItem: [{ position: 20 }]
  @UI.fieldGroup: [{ qualifier: 'Manager', position: 10 }]
  ContractManager1,

  Status,
  _Manager
}

The most common annotations

@UI.lineItem — shows the field as a column in the List Report table.
@UI.selectionField — turns it into a filter in the search bar.
@UI.identification — shows it in the Object Page header.
@Consumption.valueHelpDefinition — links a value help (F4) to a specific CDS.
@Semantics — marks fields with special meaning (currency, quantity, email...) so the UI formats them automatically.

Value Help: a CDS as a search-help source

Any CDS view can act as a value help for another field, providing a filterable list of values straight from the database.

ABAP CDSZI_VH_CONTRACT_MANAGER.ddls

@ObjectModel.usageType.serviceQuality: #X
@ObjectModel.usageType.sizeCategory: #S
@ObjectModel.usageType.dataClass: #MASTER
define view entity ZI_VH_CONTRACT_MANAGER
  as select from I_BusinessPartner
{
  key BusinessPartner  as Manager,
      BusinessPartnerFullName as ManagerName
}

Why the Interface/Consumption split matters: it lets you reuse the same data model for several consumers (a Fiori app, a report, an API) without duplicating selection logic — only the annotations of each exposure layer change.