Скачать или смотреть Extending and relating entities in SAP Cloud Application Programming Model

In the previous back-to-basics episode (https://www.youtube.com/live/ulTfUkAJ...) we used a very basic relationship to join a remote service to a local service. In this episode we put down the sledgehammer and use something more precise to build better relationships between entities.

Topics:
CAP, CDS, OData, terminal slides, singletons, foreign keys, managed associations, mashups

Links:
This week's SAP Developer News: https://groups.community.sap.com/t5/a...
SAP CodeJam group: https://groups.community.sap.com/t5/s...
OData V4 and SAP Cloud Application Programming Model talk content: https://github.com/qmacro/odata-v4-an...
Default project layouts in CAP: https://cap.cloud.sap/docs/get-starte...
All our HandsOnSAPDev live stream episodes:    • Ep.0 – Getting our feet wet  

Chapters:
00:00 Welcome and introduction
06:40 Remembering where we left off last time
10:30 Thinking about what we have in terms of the current local & remote entities
13:25 Using the Large Hadron Collider to explain the current way we're bringing the entities together
15:30 Removing the Participants entity projection from srv/show.cds
16:55 Learning about different OData V4 entities from the error we get
18:10 Looking at the slides from a talk on OData V4
19:22 Creating srv/mashup.cds as the basis of a cleaner and more gentle integration
20:39 Meditating on the meaning and purpose of the 'extend' keyword
22:50 Adding a temporary entity with an in-line definition
25:05 Considering the rules on how CDS definitions are auto loaded
26:35 Adding the Participants projection back in, but at the srv/mashup.cds layer
29:00 Moving to the next stage and wrapping the external entity with a projection definition with a vastly reduced number of properties
31:07 Creating srv/external/index.cds to contain this new definition
31:55 Talking about the background to why 'index' files work the way they do
34:10 Defining the CommunityMember projection to have only two (renamed) properties
37:15 Focusing on how we don't need (and the CDS Extension in VS Code removes) the trailing '/index.cds' from a using statement
38:53 Moving the new content from srv/show.cds to the correct file srv/mashup.cds
39:45 Thinking about the different layers (persistence, service, mashup and external) and how they relate and combine
42:24 Noting that the srv/external/index.cds is now being loaded, and understanding why
43:30 Looking at the new lightweight Participants entity type definition in the OData service
45:00 Checking out the Capire documentation on how definitions are loaded
46:05 Removing a redundant 'using' statement from srv/mashup.cds (thanks Tanmoy)
47:50 Thinking about how we might extend the Episodes entity with an association to Participants
50:00 Starting out with a simple extension with a basic property
51:10 Replacing the basic property with a participants property as an association to our new CommunityMember entity (which in turn is a simple wrapper around the A_BusinessPartner entity)
53:20 Reminding ourselves about what managed associations in CDS do for us
54:43 Showing the reduced data in the new Participants entity set
56:32 Noting the new, automatically added participants_ID property in the Episodes entity (for the foreign key relationship)