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Use Aspects, Association and Convert OData V4 to V2 using Proxy
Two halves that turn out to belong together: aspects and associations in the model, and then the v4-to-v2 proxy in front of it. The model decides what the proxy has to carry, which is why the author put them in one post.
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ODataODataExposing data and operations through OData, including the service model, metadata and protocol versions clients require. Version differences affect which clients can consume a service and which query features they can use.Data modellingData modellingDefining the shape of data before anything serves it: entities and their types, how they relate, and the projections and views that services and applications consume.
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rahul_rajagopalauthor
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CDS Associations & JoinsCDS Associations & JoinsA Devtoberfest 2026 session from SAP's performance and scalability team on what an ABAP CDS association becomes on SAP HANA, taken as an excerpt from their internal performance training. The CDS edge rests on the three ways an association is used: a path expression and an explicit join both put a left outer join into the generated view, while exposing the association leaves the view without one and adds the join only for a query that asks for its fields, which the session calls join on demand. The data modelling edge is the advice that follows and the demo under it — cardinality written as precisely as the data allows, because the optimiser trusts it, shown with a view whose missing cardinality let SELECT COUNT(*) prune the join and return 18 rows where selecting the columns returned 56, plus the left-hand, right-hand and left-outer-to-inner rewrites that correct cardinalities make possible.SAP Developers, published 2026-10-12
What's new with draft handling in RAP?What's new with draft handling in RAP?An ABAP-day session at Devtoberfest 2026 on two additions to draft handling in RAP: collaborative draft, where two users work on the same draft instance and a field is locked only while the other is in it, and draft scope, where editing an instance of one draft-enabled business object puts the related instances of a dependent one into draft as well. Andre Fischer shows what each costs in the behaviour definition and projection, the draft query view and its DCL that collaborative draft needs over a table-based business object, and the CDS table entities that remove both the draft query view and the persistence table, with their current restrictions in ABAP analytics and extensibility; the from-scratch generator in ADT grows a checkbox for them. Both demos run against the DMO flight scenario of SAP-samples/abap-platform-refscen-flight, and the last part hides the draft-related features of an OData V4 app in its manifest, which the session gives as the reason a simple create-update-delete app no longer needs a V2 service binding.published 2026-09-21
052: 10 Minutes from Start to Launchpad052: 10 Minutes from Start to LaunchpadWalks a RAP application from a root CDS view entity through a consumption projection and its associations to a metadata extension: a facet per field group, a hidden field via UI.hidden, and a selection field on the ABAP package, all in a Customer-layer DDLX source read by the generated Fiori elements app. It then covers the parts ABAP CDS modelling and annotation stop short of — service definition and binding, generating the UI in Business Application Studio, and wiring the deployed app into the Fiori Launchpad through an IAM App and business catalog.Björn S., published 2026-09-07
Beyond READ_TEXT: Decoding SAPscript Long Texts (STXL) with SQLScript in CDS/AMDPBeyond READ_TEXT: Decoding SAPscript Long Texts (STXL) with SQLScript in CDS/AMDPSTXL stores a SAPscript long text as a compressed ABAP cluster container — LZ77 plus canonical Huffman — so the only official reads are READ_TEXT, one call per text, and its mass variant READ_TEXT_TABLE, both of which ship every decompressed line to the application server and stay invisible to ABAP CDS. The author reverse-engineered that on-disk format and ported the decoder into SQLScript, wrapped in an AMDP procedure and exposed through CDS table functions, turning long texts into a joinable, filterable column read directly in the database. On ABAP 7.56 a table function needs the driver-and-filter pattern shown because a parameter cannot bind to a calling column; on ABAP 7.58/S/4HANA 2023 the same result becomes a parameter-less CDS scalar function with true filter push-down.aamelin1, published 2026-08-20
A Guide to CDS Metadata Extensions, Fiori App Generation and SAP UI5 Controller ExtensionsA Guide to CDS Metadata Extensions, Fiori App Generation and SAP UI5 Controller ExtensionsWalks through a RAP-based Fiori elements app end to end: layering UI annotations onto a CDS view through a separate ABAP metadata extension object, gated by @Metadata.allowExtensions on the base view and ordered across extensions by a required @Metadata.layer value. Generates the app in SAP Business Application Studio from the published OData V4 service's merged $metadata document, then adds an SAP UI5 controller extension — registered in manifest.json against a Fiori elements lifecycle hook — only for behaviour the annotations cannot express.ankitapaul229, published 2026-07-27
The Fourth Way to Go Offline in UI5 (And Why the Service Worker Stays Dumb)The Fourth Way to Go Offline in UI5 (And Why the Service Worker Stays Dumb)Reporting on the UI5Con session run by Viktor Sperling and Lars Kissel, the post proposes a fourth offline architecture for a warehouse scanning app: a service worker kept deliberately ignorant of OData, and a JSONModel/IndexedDB layer that does an explicit download, work, submit cycle, queuing local mutations before posting one $batch with a single changeSet at the end of a session. It also works through the alternative v4.ODataModel change-buffer pattern (updateGroupId, submitBatch) and explains why Fiori elements' annotation-driven, live OData V4 interactions resist offline replay. The session-token and XSRF-expiry problem for long offline periods is named as an open gap rather than solved.Noel_Hendrikx, published 2026-07-15
From SEGW to @OData.publish: Expose Your CDS View as OData in S/4HANAFrom SEGW to @OData.publish: Expose Your CDS View as OData in S/4HANAWalks through exposing an ABAP CDS view as an OData service in an on-premise S/4HANA system by adding the @OData.publish: true annotation, then registering and activating the generated service in SAP Gateway (transaction /IWFND/MAINT_SERVICE) before testing it with $filter, $top and $count. It sets this against the manual route through transaction SEGW, since the annotation generates the service, its navigation properties and its OData properties straight from the CDS view without a Service Builder project.rupalipunekar1234, published 2026-07-09
How to rename an OData V4 service?How to rename an OData V4 service?Renaming an OData V4 service binding changes its Service Alias and the resulting service URL, breaking any app already deployed against the old one — shown on a /DMO/TRAVEL-based example in the SAP BTP ABAP environment by unpublishing, renaming and republishing the binding, then reading the new URL back from the OData V4 service catalog's ServiceGroups entry. It weighs that against two alternatives: adding a second service definition and publishing it as a new service version under the same binding, or creating an entirely new service definition and binding, which keeps the original URL live during the cutover.published 2026-07-04
Deep Insert in SAP CAPM Using Composition and Fiori ElementsDeep Insert in SAP CAPM Using Composition and Fiori ElementsParent and children created in one transaction, which composition already gives you in the model — the post is about what Fiori elements does with it, and what the payload looks like when the UI sends both at once.published 2026-05-22
Adding Immutable Blockchain Proofs to SAP With CAP - Cardano and OData V4Adding Immutable Blockchain Proofs to SAP With CAP - Cardano and OData V4The write-up behind ODATANO, by its author: how a public blockchain gets reachable from CAP as an ordinary OData V4 service rather than through a bespoke client. The premise it starts from is worth the read on its own — SAP systems are trusted but mutable, which is what an immutable anchor is for — and Cardano is chosen for peer-reviewed research and formal methods rather than for popularity. Written as an experiment with feedback invited, not as a recommendation.maxalexweber, published 2026-05-15
OData $batch Deleting Records Across Multiple Tables in Single TransactionOData $batch Deleting Records Across Multiple Tables in Single TransactionWalks through implementing a multi-table DELETE inside a single OData v2 $batch changeset on SAP Gateway: setting cv_defer_mode = abap_true in CHANGESET_BEGIN so more than one delete is collected per change set instead of being executed immediately, looping the collected operations in CHANGESET_PROCESS to delete from each backend table in turn, and issuing one COMMIT WORK in CHANGESET_END so all tables commit or roll back together. The example is a supplier master spread across basic, address, identification and purchasing-organisation tables, deleted as one logical unit of work instead of one HTTP call per table.Abhi_0118, published 2026-04-17
Extending Standard S/4 HANA OData API'sExtending Standard S/4 HANA OData API'sWalks through extending a standard S/4HANA OData API with a custom field, preferring OData V4 over V2 for its closer OASIS compliance and simpler service enablement, then tracing the extensibility objects documented for the entity before touching any code. The custom field reaches the API by layering three CDS view extensions — extendView on I_Product, extendViewEntity on R_ProductTP and on A_Product_3 — following the projection chain down to where the base table is first selected, built in ABAP Development Tools for Eclipse.JuanDK78, published 2026-04-08
Moving from Hub Gateway to Direct S/4HANA OData V4: A Customized Reusable RAP Processing FrameworkMoving from Hub Gateway to Direct S/4HANA OData V4: A Customized Reusable RAP Processing FrameworkA generic base class for RAP custom-entity query providers — one implementation of IF_RAP_QUERY_PROVIDER~SELECT, subclassed per entity — lets a service expose OData V4 directly from S/4HANA instead of through a separate Gateway Hub. The framework loads entity configuration, extracts the request context, fetches and transforms backend data into the target entity shape, and returns it through the RAP response object, with field mapping and conversion exits left for each subclass to fill in.AnslemArnolda, published 2026-04-07
Calculating IBP Technical Week "Key Figure Date" in S/4HANA Using CDS ViewCalculating IBP Technical Week "Key Figure Date" in S/4HANA Using CDS ViewA custom ABAP CDS view entity, selecting from the standard I_CalendarDate view, to derive the first date of an SAP IBP "technical week" — the split IBP applies when a calendar week crosses a month boundary, a date S/4HANA does not expose natively. The calculated field is built with a case/when expression over dats_add_days, giving any calendar date's technical-week key figure date.bharatbajaj, published 2026-02-18
UI for the BTP Application Vulnerability ReportUI for the BTP Application Vulnerability ReportAn open-source SAPUI5 front end for SAP's Application Vulnerability Report API, backed by a CAP Node.js service that projects the external findings as an OData V4 entity and forwards each query with api.run(req.query). The CAP service reaches that API through a Destination service instance configured with OAuth2ClientCredentials authentication from a service key, so the address and credentials stay out of the application code.published 2026-02-10
Building an Enterprise Application Using Fiori Elements and CAP - Part 1Building an Enterprise Application Using Fiori Elements and CAP - Part 1Part one of three, and it is all backend: the CAP service the UI will sit on. The author states the constraint the series works under — simple enough for someone new to the stack, without departing from the standard project layout.Farooq, published 2025-12-10
S/4HANA公有云版的内部ABAP拓展S/4HANA公有云版的内部ABAP拓展Argues that S/4HANA Cloud public edition's in-app ABAP extensibility is still real ABAP development, just under stricter rules: developer extensions require ABAP Development Tools rather than SAP GUI transactions, data models are defined as CDS views instead of SE11 tables, business logic is a RAP behavior definition instead of a function module, and service exposure is an auto-generated OData service from a Service Definition instead of a hand-built RFC/BAPI. The piece walks a worked example — a Fiori app that triggers the Purchase Requisition API — through CDS, RAP, OData activation on SAP Gateway, and authorization via business catalogues, and frames the whitelist of released APIs and CDS views as upgrade-safety rather than a restriction.ArthurYang, published 2025-11-24
OData Deep Insert: Implementation and Real-Life ExamplesOData Deep Insert: Implementation and Real-Life ExamplesWalks through implementing OData Deep Insert on classic SAP Gateway: two entity types joined by an association in SEGW, and a redefined CREATE_DEEP_ENTITY method in the DPC_EXT class that unpacks the header and item payload and calls BAPI_SALESORDER_CREATEFROMDAT2 to create a sales order with its line items in one request instead of separate calls per item. Gives a sample JSON payload to test with Postman or /IWFND/GW_CLIENT and names the usual failure points — an unmapped association, a method that was never redefined, or a commit left out after the BAPI call.SRSATAPATHY, published 2025-09-15
Create CDS Views and expose through OData service in CAPMCreate CDS Views and expose through OData service in CAPMViews defined in CDS and then exposed, which is the whole of what a small CAP service is. Written step by step from cds init onward in Business Application Studio.VenkateshMundru, published 2025-08-11
Step-by-Step Guide to Display System Details on SAP Fiori Launchpad ShellStep-by-Step Guide to Display System Details on SAP Fiori Launchpad ShellA step-by-step build of a plugin for the SAP Fiori launchpad shell that shows the system ID and client on every app it hosts: an OData service modelled in SAP Gateway Service Builder (SEGW), its GetEntitySet method redefined to call the function module RSAPI_CTC_GET_SYSTEM_DETAILS, then consumed from a project in SAP Business Application Studio with the Component.js and manifest.json changes a shell plugin needs instead of a standalone app. It covers the registration step a plugin needs beyond a normal Fiori app: a Catalog and Target Mapping with Semantic Object Shell and Action Plugin, deployed on-premise and assigned to roles.RahulManchala, published 2025-07-30
The Complete Guide to Calling Actions in UI5 with Custom CodeThe Complete Guide to Calling Actions in UI5 with Custom CodeWritten because the documentation is thin and the samples sparse, and openly as a note to the author's future self — hand-coding an action call has become a rare task for anyone mostly working in Fiori elements, which is exactly why it is hard to look up when it comes round. Comes with a CAP sample project, so the service half is there too.published 2025-07-21
A CAP Plugin for Flexible Number Range Management: cds-numberrange-pluginA CAP Plugin for Flexible Number Range Management: cds-numberrange-pluginThe author's own plugin, and the reason given for writing it is about plugins rather than about number ranges: a year of using them convinced them that this was the way to extend CAP without leaving marks on the application. Sequential document numbers are the thing it does; keeping the host project clean is the thing it argues for.abdulbasit, published 2025-06-17
Understanding Projections in CAPM: Select Only What You Need!Understanding Projections in CAPM: Select Only What You Need!One concept, explained by someone who had just learned it and says so — what a projection is, why it matters, and an analogy. The register is unusual here and suits the subject: projections are the first thing that makes CDS feel different from a table.Avisek_, published 2025-06-10
How to Perform Initial Loads from S/4HANA to Advanced Event Mesh with Odata PollHow to Perform Initial Loads from S/4HANA to Advanced Event Mesh with Odata PollWalks through building a Cloud Integration flow that polls the S/4HANA Business Partner OData API on a timer, splits the response into individual records, and publishes each as an event to Advanced Event Mesh through its adapter, with the topic set dynamically from a grouping property. Selects fields and expands associations with $select/$expand against an EDMX from the API Business Hub, and works around the OData V2 adapter's lack of JSON support by falling back to the HTTP adapter with an XML-to-JSON converter. Flags the trade-off: the pattern needs no backend change beyond activating the API, but the polled payload has to stay aligned with whatever event format the ERP pushes on change.AlexPfeil, published 2025-04-04
Generating Adobe Form Using RAP framework OData ServicesGenerating Adobe Form Using RAP framework OData ServicesModels a RAP root view entity and consumption view over a custom sales-order table, built with ABAP CDS, and exposes it through a service definition and an OData V2 UI service binding. A separate SEGW project implements GET_STREAM to call an Adobe Form driver class and stream the rendered PDF back as the response, with a computed link field added to the CDS view so the UI can open it. The PDF is generated in the backend and returned to the calling program rather than sent straight to a printer.Megastar, published 2025-03-18
My CAP Projects ToolboxMy CAP Projects ToolboxA working inventory of daily CAP tooling: scaffolding a project with cds init and growing it facet by facet through cds add (TypeScript, seed data, an .http test file, a handler stub), then running it with cds watch and setting a breakpoint in a custom handler from SAP Business Application Studio's JavaScript Debug Terminal. It also walks through an @open entity that accepts properties the model never declared, and reading temporal data defined with CAP's temporal aspect, where a plain read returns only what is valid now and a custom handler is needed to retrieve every time slice.vvdries, published 2024-12-23
SAP Incentive Management - Understanding of CSN file & CLI Command to generateSAP Incentive Management - Understanding of CSN file & CLI Command to generateCSN met from the far end: not as CAP's compiled model but as the interchange format a product hands to Analytics Cloud so a story knows the shape of the data. Explains what CSN is, why the format matters here, and the command that produces one.Yogananda, published 2024-11-19
Calling bound / unbound CAP actions from Fiori elements application.Calling bound / unbound CAP actions from Fiori elements application.invokeAction from the Fiori elements Edit flow API, with the difference between bound and unbound actions spelled out first because the call shape differs. Under three thousand characters and it answers exactly one question.vidhyasagarmule, published 2024-09-07
CAP, CDS, CDL, CSN and jq - finding associationsCAP, CDS, CDL, CSN and jq - finding associationsHow associations are actually represented once CDL is compiled into CSN, worked out by parsing the machine-readable form with jq. Useful less as a recipe than as a way in: anything that wants to reason about a CDS model without the compiler has to read CSN, and this is what that looks like from the outside.published 2024-04-16
Graph intro series, part 8: Use Graph With OData v4Graph intro series, part 8: Use Graph With OData v4Part eight of the Graph intro series works through querying SAP Graph's unified business data graph over OData v4: inspecting the $metadata EDMX document for an entity type such as SalesQuote, then shaping the response with $select and nested $expand across navigation properties, and paging a collection with $filter, $orderby, $top and $skip. It stays with the protocol mechanics against the Graph sandbox endpoint rather than any one client library.florian_moritz, published 2024-03-19
SAP CAP(Cloud Application Programming)开发框架概述SAP CAP(Cloud Application Programming)开发框架概述A Chinese-language walkthrough of CAP built mainly from CAPire's own "About CAP" page: CDS entities, associations, compositions and aspects for data modelling, with an extend Books with @restrict: [{ grant:'WRITE', to:'admin' }] aspect as its authorization example; CQL and CQN queries shown against both a local service and OData's $select/$expand; and the service-and-event model — this.on, this.emit, srv.on — that carries CAP's async processing. It closes with the author's own setup: installing @sap/cds-dk, scaffolding a bookshop project with cds init, and running it with cds watch against local SQLite, mocked authentication and file-based messaging standing in for HANA Cloud, IAS and Kafka.ArthurYang, published 2024-01-07
Exposing Calculation View with Dynamic Client via OData APIExposing Calculation View with Dynamic Client via OData APIGetting a HANA Cloud calculation view — built in Business Application Studio and deployed to an HDI container, which is the recommended way to build native HANA artifacts — out through an OData API. The gap it fills is the one between HANA-native development and a service a client can call, which CAP does not cover for artifacts it did not generate.published 2023-10-04
#CAP-TechBytes Input Validation#CAP-TechBytes Input ValidationThe annotations one at a time — @mandatory, @assert.unique, @assert.range including the enum form, @assert.format — each with what it produces. Ends on error handling, which is the part that decides whether any of it is usable from a UI.Thajunniza, published 2023-07-07
#BTP #SAPCAP: Quirky Nuggets (N03-N04)#BTP #SAPCAP: Quirky Nuggets (N03-N04)Two unrelated findings in one post, which is the format of the series: the OData operators tried against a CAP service — with a schema of deliberately awkward types to try them on — and undeploying database artifacts, which is the half people hit in anger. Numbered N03 and N04 of a run that continues either side.Ajit_K_Panda, published 2023-06-05
#BTP #SAPCAP: Quirky Nuggets (N03-N04)
Deployment changed in @sap/cds-dk 8.9.0, 2025-03-31. Affects A recipe, Runnable code.
#BTP #SAPCAP: Quirky Nuggets (N01-N02)#BTP #SAPCAP: Quirky Nuggets (N01-N02)Walks through two CAP gotchas: the on/before/after phases of custom event handlers, shown with an after handler whose edits only reach the result when the handler returns an object or array, never a primitive; and the @assert.unique annotation, which builds a database uniqueness constraint from the model. For Input validation, the catch is that once the constrained property is nested, @assert.unique must name it by its model dot path (assignment.type) rather than the flattened column data modelling compiles it to (assignment_type).published 2023-06-05
[Part – 2] Enrich CAP based Services with Behaviors using Annotations[Part – 2] Enrich CAP based Services with Behaviors using AnnotationsThe second half of a two-part walkthrough of CAP's behavioral annotations, following on from access control and input validation in the first part. This post works through @cds.autoexpose, @cds.api.ignore, @cds.persistence.exists/skip, @cds.on.insert/@cds.on.update and the @odata.Type/@odata.singleton mapping overrides, all shaping how a CDS model is projected into a service, which is data modelling. Alongside these it covers @cds.query.limit for default and maximum page sizes (pagination and streaming), @odata.etag with exclusive and shared locks for optimistic concurrency (concurrency control), and @cds.search for scoping $search to chosen elements (search), each with a CDS code example.published 2023-01-29
SAP CAP function and action with Unstructured/Dynamic Type Input/OutputSAP CAP function and action with Unstructured/Dynamic Type Input/OutputA CAP action or function can take or return an unstructured type: annotate the service @protocol: 'rest', declare the parameter or return value as @open type object {}, and a handler shapes the payload however a given request needs, shown here with a bound action and a function that returns a different structure per input. The text states plainly that OData V4 and GraphQL services require a fixed structure for action and function parameters, so the dynamic type works only over CAP's REST protocol.published 2022-12-08
Understanding entity relationships in CDSUnderstanding entity relationships in CDSModels a CAP task-management domain in CDS — Users, Roles, Tasks and Categories joined by to-one associations, a composition of tasks owned by a user, and a self-referencing association from a user to its parent — using the managed and cuid aspects from @sap/cds/common. It then visualises that model in Business Application Studio's CDS Graphical Modeler and adds a CAP Java before-handler that sets a generated password on user creation.Avinash_Vaidya, published 2022-11-22
Messaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client ApplicationsMessaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client ApplicationsGetting a message out of a CAP service and onto a Fiori elements object page in a draft scenario — errors, warnings and information, each of which the UI treats differently. Co-written with one of the people on the OData side, and it spends its length on the message container rather than on the handler that fills it.arley-triana-morin, published 2022-08-11
Messaging System for Transferring Error, Warning, and Information Messages from OData V4 Services to HTTP Client Applications
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects A recipe, Runnable code.
Extend SAP SuccessFactors on SAP BTP with CAP - Create the CAP ServiceExtend SAP SuccessFactors on SAP BTP with CAP - Create the CAP ServiceWalks through writing a service definition in SAP Business Application Studio that projects entities from an existing CDS model: one entity gets @odata.draft.enabled because Fiori Elements only shows CRUD actions on a draft-enabled entity, and a read-only projection of an already-imported SuccessFactors OData entity fails with the generic handlers because the call is delegated to the remote service, so a custom handler is needed. Running cds watch then serves the entities, drafts and $metadata at the declared service path.published 2022-03-23
SAP CAP Recent Enhancements the HANA Dev Should Know AboutSAP CAP Recent Enhancements the HANA Dev Should Know AboutThomas Jung walks through CAP features for HANA database developers that landed through late 2021: doc comments in the data model (CDL comments propagated into generated database objects via the package.json cdsc.docs compiler option), and schema evolution reaching general availability in the November 2021 release, using the @cds.persistence.journal annotation and cds.hana.journal settings to generate incremental hdbmigrationtable migration scripts instead of dropping and recreating tables. It also walks through two features outside those two: window functions in view column definitions, added in the December 2021 release, and a beta assert_integrity setting that generates database foreign-key constraints from 1:1 associations and compositions.published 2022-02-15
SAP CAP Adapter to expose OData as custom REST ServiceSAP CAP Adapter to expose OData as custom REST ServiceWalks through consuming an external OData V2 service in a CAP project — cds import converts the Northwind service's EDMX into a CSN and cds.connect.to wires up the remote proxy — then re-exposing it as plain REST with the @protocol:'rest' annotation instead of OData's own envelope. Shows two ways to reshape the response, renaming and dropping fields in a CDS projection or rewriting the returned objects in a custom service handler, and remaps ?pageSize and ?offset onto OData's $top and $skip in that same handler.Former Member, published 2021-09-15
Dynamic OData from "any" API through SAP BTP KymaDynamic OData from "any" API through SAP BTP KymaPutting an OData face on a third-party API by way of Kyma, so the SAP side of a landscape can consume something that was never built for it. The word dynamic is doing work in the title — the shape is not modelled in advance.Gunter, published 2021-09-09
Create a Business Service using CDS, Node.js, SQLite and a OData serviceCreate a Business Service using CDS, Node.js, SQLite and a OData serviceThe stack at its smallest — CDS, Node, SQLite, an OData service — worked through at length. Nothing cloud in it, which is the point: it is the shape of a CAP service before any of the platform arrives.raybanton, published 2021-07-12
Create a Business Service using CDS, Node.js, SQLite and a OData service
Database connectors has changed twice since this was published, most recently in @sap/cds 10.1.0, 2026-09-07. Affects A recipe, Runnable code.
Creating structured types, enums and named aspects using the CDS Graphical ModelerCreating structured types, enums and named aspects using the CDS Graphical ModelerThe modelling constructs that are awkward to draw — structured types, enums, named aspects — done in the graphical modeller rather than in CDL.Xiao-fei_Song, published 2021-05-26
SAP Tech Bytes: Adding Service Implementation to an SAP HANA ProjectSAP Tech Bytes: Adding Service Implementation to an SAP HANA ProjectThomas Jung converts an existing SAP HANA-only project into a CAP one, exposing its native tables, views and a calculation view as CAP service entities with @cds.persistence.exists so they get full create, update, delete and read operations without being redefined. He adds OData V2 support through an adapter proxy for callers still expecting XSODATA-shaped responses, and separately turns on CAP's OpenAPI generation with its Swagger UI test tool. A second part rebuilds the same service layer with a standalone Node.js module instead of CAP, for cases that need more control than CAP's REST or OData defaults give.published 2021-05-07
The End2End Journey: Advocates Service – CAP Service, OData V2/4 & REST in One single ProjectThe End2End Journey: Advocates Service – CAP Service, OData V2/4 & REST in One single ProjectOne CAP service exposing OData V2, OData V4 and REST at the same time, which is unusual enough to be worth the read on its own. Part of an end-to-end series, deployed on Cloud Foundry against HANA Cloud, so the protocol question sits inside a whole application rather than a snippet.KRiedelsheimer, published 2021-05-06
The End2End Journey: Advocates Service – CAP Service, OData V2/4 & REST in One single Project
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects A recipe, Runnable code.
Importing @sap/cds common.cds to your CAP project using the CDS Graphical ModelerImporting @sap/cds common.cds to your CAP project using the CDS Graphical ModelerPulling the common aspects and code lists from @sap/cds into a model through the modeller, so the reuse types appear in the diagram rather than only in the file.Xiao-fei_Song, published 2021-05-06
Custom Functions in OData V4 – SAP Cloud Application Programming ModelCustom Functions in OData V4 – SAP Cloud Application Programming ModelFunctions rather than actions, and the distinction is where it starts: a function must return data and must never change any, so it is the read-only half of custom operations. Then how to declare and implement one on a CAP service.Roopa_N, published 2021-04-28
Custom Functions in OData V4 – SAP Cloud Application Programming Model
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects A recipe.
SAP BTP SDK for iOS & CAP with OData V4 supportSAP BTP SDK for iOS & CAP with OData V4 supportThe iOS SDK gaining OData V4, which until then made connecting a native app to a CAP service awkward — CAP defaults to v4 and the SDK did not speak it. Short, and it marks the date that stopped being a problem.KRiedelsheimer, published 2021-04-21
Is it time to switch to OData v4?Is it time to switch to OData v4?A recommendation with its caveat attached: use v4 on new projects, and be aware it is less mature than v2 in terms of what the SAP stack around it supports. Written after using it on a real extension project, which is what makes the caveat credible.MikeDoyle, published 2021-02-05
First Java Cap ApplicationFirst Java Cap ApplicationA step-by-step walkthrough of a first CAP Java project: com.sap.cds:cds-services-archetype scaffolds the initial Maven project, and the domain model is then rewritten in the db folder with entities, the cuid and managed aspects, associations, compositions and a CodeList, so a hand-coded event handler serving a single entity gives way to a service that CAP's generic persistence handling serves without custom code. It deploys that model to SQLite for local development — cds deploy --to sqlite, then a Spring profile pointing at the generated database file — and ends by adding an index.cds so the model and service can be published as a reusable npm module.bruce_wang3, published 2020-12-08
SAP HANA XSA pt. 2 – Smart variants, OData v4 -> v2SAP HANA XSA pt. 2 – Smart variants, OData v4 -> v2Smart tables and smart variants against an OData v4 service, with the v4-to-v2 conversion that the smart controls needed at the time. The second part of an XSA series, written from Tokyo in a summer the author mentions.Gunter, published 2020-08-27
Resolving date serialization issues when using an external OData v2 service with CAPResolving date serialization issues when using an external OData v2 service with CAPDates coming out of an external OData v2 service in a shape CAP does not expect, and what to do about it. A narrow bug report with a fix, and the kind of thing that costs an afternoon if nobody has written it down.pieterjanssens, published 2020-07-09
How to add OData v2 adapter proxy to your CAP projectHow to add OData v2 adapter proxy to your CAP projectThe problem is stated in one line — a UI5 application that only speaks OData v2 in front of a CAP service that speaks v4 — and the answer is a proxy in the middle rather than a rewrite of either end. Written while v4 support in the UI5 stack was still patchy, which is the whole reason the adapter exists.published 2020-06-30
How to add OData v2 adapter proxy to your CAP project
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects Runnable code.
Developing Business Services with Cloud Application Programming(CAP) Model in SAP Business StudioDeveloping Business Services with Cloud Application Programming(CAP) Model in SAP Business StudioA step-by-step build of a CAP Node.js service in SAP Business Application Studio: a CDS schema for banks, customers, accounts and transactions using compositions, associations, enumerated types and the @assert.unique constraint, followed by authorization layered on with @restrict and @requires annotations and mock users assigned the authenticated-user and Manager roles in .cdsrc.json. Custom event handlers registered through @sap/cds (srv.before/srv.after) and sample HTTP requests round out the example.Ranjith, published 2020-05-27
Computed field example in CAPComputed field example in CAPAn answer to a Community question — how to count the entities on the far side of an association — written up as a short post rather than left in a thread. The answer combines CDS with Node.js service events, which is the seam worth noticing: some of what looks like modelling is expressed in the model and some has to be computed when the request arrives, and the boundary between them is not obvious from either side.published 2019-08-21
Computed field example in CAP
Data modelling has changed 3 times since this was published, most recently in @sap/cds 9.9.0, 2026-04-23. Affects A recipe, Runnable code.
SAP Cloud Application Programming Model: Deep Insert (5) Consume Remote Service with SAP Cloud SDKSAP Cloud Application Programming Model: Deep Insert (5) Consume Remote Service with SAP Cloud SDKThe same thing again through SAP Cloud SDK, published as a deliberate comparison with the part before it — the author says outright that it does what the previous post did, differently. Reading both is how you see what the SDK is actually doing for you.CarlosRoggan, published 2019-07-26
SAP Cloud Application Programming Model: Deep Insert (5) Consume Remote Service with SAP Cloud SDK
Destinations changed in @sap-cloud-sdk/connectivity 4.0.0, 2025-03-04. Affects Runnable code.
SAP Cloud Application Programming Model: Deep Insert (4) Consume Remote ServiceSAP Cloud Application Programming Model: Deep Insert (4) Consume Remote ServiceFourth in a long series on deep insert, and the one where the target stops being local. Twenty thousand characters, project files linked, and the earlier parts on UUIDs and multi-level structures are prerequisites the author names.CarlosRoggan, published 2019-07-24
SAP Cloud Application Programming Model: Deep Insert (4) Consume Remote Service
Destinations changed in @sap-cloud-sdk/connectivity 4.0.0, 2025-03-04. Affects A recipe, Runnable code.
SAP Cloud Platform Backend service: Tutorial [11]: CDS : magic: key: generationSAP Cloud Platform Backend service: Tutorial [11]: CDS : magic: key: generationExplains CDS's UUID key type: giving a key property UUID gets its value generated automatically instead of a hand-picked unused number, as data modelling lets an element's type do, at the cost of a 36-character value unfit for a user-facing display. It then works out how that generated value is addressed in a single-entity read URL — bare brackets in OData V4 against the guid'...' literal V2 requires — citing the OData specification for the difference.CarlosRoggan, published 2019-03-15
Develop a full stack Business application with SAP Cloud Application Programming ModelDevelop a full stack Business application with SAP Cloud Application Programming ModelBuilds a full-stack CAP application in SAP Web IDE Full Stack's now-retired 'SAP Cloud Platform Business Application' template: a data-model.cds entity with its own service definition, then Fiori annotations on the generated OData. Building the project compiles that model into Catalog.xml and csn.json, the EDMX and CSN that metadata publishing says every exposed service gets. The entity and service definitions it writes by hand are the basic shape data modelling covers, though the webIDE and MTA tooling staged around them is gone.former_member584731, published 2018-11-29
Consume Remote Services in a Full-Stack CAP ApplicationConsume Remote Services in a Full-Stack CAP ApplicationExtending the Developer's Guide application with a remote S/4HANA service — connectivity, importing the Business Partner API, and running against it. SAP publishes this as four separate paths: mock server or real S/4HANA Cloud, times Cloud Foundry or Kyma. One entry covers all four, because the difference between them is which backend and which runtime, not what you learn.SAP
Extend SAP SuccessFactors on SAP BTP with the SAP Cloud Application Programming ModelExtend SAP SuccessFactors on SAP BTP with the SAP Cloud Application Programming ModelTwelve tutorials, about two hours, building a side-by-side extension of SuccessFactors on BTP. The spine is remote services: importing the SuccessFactors OData service definitions into a CAP model, then treating them as entities the extension reads and writes through, rather than as an API called from a handler. Indexed as one entry because the parts only make sense in order.SAP
OData entity as a governed query surface for agents, not a toolOData entity as a governed query surface for agents, not a toolAn OData entity, generated from the annotations a service already carries, as the surface an agent queries over SAP data: filterable, selectable and sortable fields, authorisation injected on the server side, and a bound query cost, instead of the entity as a tool. SAP's abstract sets this against the MCP gateway in SAP Integration Suite, where exposing an API is the easy part and getting an agent to pick the right one is not, which is the tool governance concern read through OData. A TechEd 2026 session (Wednesday 28 October, Berlin), presented by Aleksandr Ivanov and Evgenii Shirokikh, written here from SAP's abstract; the recording is not yet published.
AI-assisted full stack development using model context protocol serversAI-assisted full stack development using model context protocol serversMCP servers in Visual Studio Code used to configure, query and change a full-stack application built with CAP, CDS and OData: the agent access to your code concern, a coding assistant reading and changing the project it works in. The abstract names no server, so neither @cap-js/mcp-server nor any other is attached, and it does not say which changes are made. A TechEd 2026 session (Thursday 29 October, Berlin), presented by Sergio Guerrero, written here from SAP's abstract; the recording is not yet published.
SAP Fiori elements and the age of AI: Build apps that are future readySAP Fiori elements and the age of AI: Build apps that are future readyBuilding SAP Fiori elements apps so they work with AI and fit SAP's next products: the abstract names AI-assisted development, OData and annotation design, and intent- and action-ready semantics that keep an app secure, discoverable and upgrade safe. Annotation design is the Fiori annotations concern and the OData service under it the other; the atlas holds no entry for SAP Fiori elements itself, and the abstract names no tool, annotation or version. A TechEd 2026 session (Thursday 29 October, Berlin), presented by Katja Zoch and Sebastian Steinhauer, written here from SAP's abstract; the recording is not yet published.
Learn how to define constraints declaratively in your CDS modelLearn how to define constraints declaratively in your CDS modelConstraints expressed in the model rather than checked in a handler — the distinction the atlas draws between input validation the framework enforces and validation somebody writes.SAP
Explore the declarative power of status-transition flowsExplore the declarative power of status-transition flowsModelling which state a record may move to next, declaratively, rather than scattering the rule across the handlers that move it.SAP
Analyze and optimize ABAP Cloud model apps built on core data servicesAnalyze and optimize ABAP Cloud model apps built on core data servicesPerformance anti-patterns in data models built with ABAP CDS under ABAP Cloud applications, and the tools that find them: the abstract names ABAP cross trace, the SQL analyzer (PlanViz) in Visual Studio Code and the SAP HANA database explorer as what the session uses to follow a bottleneck from the application to the database. The anti-patterns are taken from real business applications, which is where the data modelling edge holds; which ones are shown is not in the abstract. A TechEd 2026 session (Tuesday 27 October, Berlin), presented by Ingo Braeuninger, Robert Werlich, Steffen Siegmund and Thomas Fiedler, written here from SAP's abstract; the recording is not yet published.
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