[WIP]Chapter 1 Modeling Your First CDS View

 

최초 작성일 : 2024-11-12

최종 작성일 : 

목표: CDS 뷰 이해하기

 

1.1 -> looking at the design of the data model of your application.

1.2 ->based on the model of the database tables, we then run through the individual, practically executale steps

for creating and changing CDS views.

you'll also learn how to use CDS views as basic building blocks for defining other CDS views as well as learn how to use CDS views ad data sources in your abap logic.

that is, you'll learn how to select data from the modeled CDS views by leveraging the ABAP SQL syntax of ABAP.

 

 

1.1 Define the Data Model of the Application

defining the fundamental data model of the application.

in this design phase, the main aim is to idenfity and name the different data sources , that is the corresponding fundamental entries that your application will be based on.

the identified entities should also be correlated to one another based on their semantic relationship.

(확인된 값들은 서로 의미적 관계 가 있어 -> RDBMS )

 

 

1.2 Implement the Data Model of the application

1)create the database table for sale order item

2)define CDS views

3)maintain the CDS view and how the maintenance steps get reflected in its activation states

4)defining a hierarchy of CDS view models

(can capture the semantic relationship of these two CDS views by means of CDS association)

 

[CDS Association] 

entity, view, key, element 및 CDS association은 CDS 문법을 구성하는 핵심요소임

CDS association을 통해서 CDS 모델 사이에 관계를 문서화하여 ERM을 생성할 수 있음

(CDS association은 CDS 모델 사이의 관계를 문서화 해주고

ERM을 생성할 수 있어)

CDS association의 기능은 1) CDE 모델 사이의 관계를 문서화 하고 2) ERM(Entity Relationship Model)을 생성함

 

CDS Associations are an important and integral part of  the CDS syntax.
(@entity, @view, association, key, element 같은 요소들은 CDS 문법을 구성하는 핵심요소들로, 이들이 빠지면, CDS의 기능을 온전히 활용할 수 없음)

Using CDS associations, you document the relationship between the CDS models, essentially creating an entity relationship model (ERM).

-> CDS associations을 사용하면 CDS model 사이의 관계를 문서화하여 ERM을 생성할 수 있어

an ERM describes a semantic data model based on entities, their relationships, and their properties.

it's the basis of many development project.

-> ERM은 엔터티, 그들의 relationship 그리고 그들의 properties를 기반으로 시멘틱 데이터 모델을 설명해줘

 

Apart from enriching the CDS models with semantic information, CDS associations can also be used for implementing CDS models and parts thereof as well as for data accesses at runtime.

-> CDS 모델은 시멘틱 정보를 풍부하게 해줄 뿐만 아니라,

CDS association의 또다른 기능은 1) CDS 모델을 실행 2) data accesses at runtime (실시간으로 데이터 접근) 하는 것임

 

then, we create another CDS view, which represents an example of a use case-specific consumption view vases on the fundamental data model of the application.

 

1.2.1 Create Database Tables

Database Tables in SAP S/4 HANA

often the database table of an application already exist like vbak.

therefor, we'll only deal with the definition of database tabls in this section.

 

Tools for creating database tables

ADT

 

Select object type to create

 

 

**semantic model : 데이터의 의미과 관계를 표현하는 모델. 데이터의 구조 뿐만 아니라 그 데이터가 나타내는 의미나 비즈니스 맥락을 포함해서 데이터가 어떻게 연결되고 이해되는지를 명확하게 정의하는 데 중점을 둠. (비즈니스의 의미를 모델에 담아내는 것)