CDS Cookbook — Practical SAP CDS & AMDP Patterns

A searchable SAP CDS and AMDP pattern library for experienced SAP developers — built for lookup, not for step-by-step learning. You arrive knowing what you need (a filtered path expression, a conditional aggregate, a table function with a recursive CTE, a plant-dependent value help), find the pattern, and adapt it.

Standard/  how SAP standard CDS artifacts are consumed, by module
Custom/    custom view entities, value helps, custom-entity + query-provider pairs
Extension/ CDS view extensions, virtual elements, SADL exits
AMDP/      CDS table functions + their SQLScript implementations
Util/       reusable building blocks: joins, aggregation, parameters, value helps

Scope & Provenance

• Everything here is user-authored — examples the author wrote, and reference notes the author took while building them.
• Standard/ does not contain copied SAP source. Those files are notes on how a standard artifact was consumed: the working element subset, the association and join shape, the filter shape. See Standard/README.md.
• SAP standard names are referenced as dependencies and interfaces. Entity names, element names, data elements and annotation vocabulary belong to SAP.
• The custom examples are genericised enterprise patterns distilled from practical S/4HANA development. Customer-specific field vocabulary, organisational scope and Customizing values are deliberately removed; custom append fields appear under neutral ZZ_* names. What remains is the structure worth reusing.
• Mainly S/4HANA on-premise oriented. Classic CDS and classic extensions are intentionally represented, because that is what on-premise projects use.
• Not official SAP documentation. Verify against SAP Help and your own system.

Highlights

• AMDP / SQLScript table functions — window functions (RANK, ROW_NUMBER), STRING_AGG, CTEs, a recursive CTE for hierarchy traversal, APPLY_FILTER with an explicit trust boundary, HANA date functions, and client-correct joins throughout.
• Standard CDS usage references across 12 modules (MM, SD, PM, QM, FI, PP, PS, EWM, MD, HR, BASIS, plus IS-OIL/TSW).
• Custom view entities — text-table associations, item/header fallback, conditional aggregation, parameters, anti-joins via IS NULL.
• Extensions — classic extend view appends across five modules, analytics query extensions, virtual elements with SADL exit classes (read + filter).
• Value-help patterns — additionalBinding, localConstant, distinctValues, fuzzy search, plus a DDIC-key → value-help index.
• Order → delivery → invoice chain — three views that model a real document-flow projection.
• Custom entity + query provider — when the result set cannot be expressed in SQL.

Guide vs Cookbook

CDSGuide is the structured route: concepts in order, syntax explained, a learning and engineering reference you read front to back. CDS Cookbook is the lookup route: production-shaped patterns you search, copy and adapt when you already know what you are doing. Same subject, opposite reading mode — and the AMDP, virtual-element and query-provider material here has no counterpart in the guide.

Pattern Categories

Organised by mechanism, which is usually how you search:

Mechanism	Where to look
Associations, filtered paths ([1: … ]), joins	Standard/**, Custom/SD, Util/LeftOuterJoin.abap
Aggregation & grouping	Util/Max.abap, Util/Min.abap, Util/Sum.abap, Standard/PM, Standard/MM
Parameters ($parameters)	Util/Parameters.abap, Custom/ValueHelp/ZSM_I_USER_STATUS_VH.abap, AMDP/Function.abap
Session variables, client handling	Standard/** ($session.system_language), AMDP/** (client parameter)
Extensions & appends	Extension/**
Virtual elements & SADL exits	Extension/PM/C_ObjPgMaintOrderAndOperation.abap, Extension/PM/C_RSHMaintSchedSmltdOp.abap, Util/Class.abap
Value helps	Custom/ValueHelp/**, Util/ValueHelp.abap, Standard/ValueHelp.txt
Table functions & AMDP	AMDP/Function.abap (contracts), AMDP/Class.abap (SQLScript)
Custom entity + query provider	Custom/Implementation/**

Repository Map

Path	Contents
Standard/<MODULE>/	User-authored reference notes on SAP standard CDS artifacts; not SAP source. See Standard/README.md
Standard/ValueHelp.txt	DDIC key field → CDS value-help entity index
Custom/SD/	Order → delivery → invoice chain (genericised)
Custom/ValueHelp/	Custom value helps + a consumption-annotation snippet
Custom/Implementation/	Custom entity and its query-provider class
Extension/<MODULE>/	CDS view extensions; two files pair an extension with its exit class
AMDP/	Function.abap = table-function contracts, Class.abap = SQLScript implementations
Util/	Reusable building blocks
User/	User master reporting view (privacy boundary documented)
List.abap	Loose ABAP SQL snippet

Most complete artifacts and mixed examples carry a short Type: and Context: line; for Standard/, the folder README carries the default.

Find a Pattern

• By module — Standard/<MODULE> or Extension/<MODULE>.
• By CDS entity name — repo search or grep for the name; files are named after the artifact.
• By field or association — search the SAP field (SalesOrganization) or association (_SalesDocumentItem); names recur across files.
• By business term — Delivery, Invoice, Nomination, Inspection, Maintenance.
• By mechanism — see the table above; or grep an annotation (@Semantics.quantity, virtualElementCalculatedBy, additionalBinding, STRING_AGG, WITH RECURSIVE).
• For a value help — start at Standard/ValueHelp.txt.

Files use the .abap extension whatever they contain (CDS DDL, AMDP, ABAP, notes) so syntax highlighting stays consistent. CDS DDL files use // comments; genuine ABAP files use ".

Compatibility / Lifecycle

• Examples span several on-premise S/4HANA / ABAP generations. Classic define view and classic extend view appends are kept on purpose alongside define view entity.
• The existence and release status of SAP standard objects varies by release, Support Package and installed industry solution. An I_, C_, R_ or P_ name alone is not a promise that the artifact is a released API in your system — P_ and R_ are private / restricted-use layers, and files referencing them say so.
• Release-sensitive features are flagged in the file that uses them (view entities, table functions, recursive CTEs, virtual elements, extension mechanisms, client-handling annotations).
• No ABAP Cloud compatibility is claimed. These patterns use direct table access, classic views, classic appends and function-module calls.
• Always validate against your target system before reuse.

Adaptation & Security Notes

• These are patterns, not drop-in solutions. Adapt names, scope and types to your model.
• Organisational and Customizing values are intentionally genericised. Where a filter is needed, the file shows where to add your own instead of shipping one installation's values.
• Authorization is your design decision. @AccessControl.authorizationCheck: #NOT_REQUIRED means no check is applied. #CHECK only takes effect when a DCL role exists — with no applicable role it protects nothing. This repository ships no DCL roles and does not invent any.
• Dynamic SQL and dynamic filters need a trusted boundary. The APPLY_FILTER recipe in AMDP/Class.abap documents this explicitly: the condition must be generated from structured, validated ABAP selection input — never a raw condition string from a consumer.
• Do not project personal data just because the source has it. Several examples deliberately omit email, phone, tax and identity fields, and say so.

Contributing

Small, focused, reversible changes:

1. One example (or one closely related group) per commit/PR.
2. Don't touch unrelated examples in the same change.
3. Fix genuine technical defects; don't rewrite working code for style. Preserve existing aliases, comments and field ordering otherwise.
4. Never leave knowingly broken syntax in place as "the example" — fix it and note the trap.
5. Keep the folder-by-module structure, and set Type: / Context: on new files.
6. Reference snippets are welcome and don't need to be activatable — label them as such.

Related Guides

Guide	Focus
ABAPGuide	ABAP language and techniques, classic to modern
CDSGuide	ABAP CDS, structured route through both generations
CDS-Cookbook (this repository)	CDS and AMDP pattern library
GWGuide	SAP Gateway: SEGW and OData V2
UIGuide	SAPUI5 and Fiori control and pattern reference
JSGuide	Plain JavaScript and browser APIs
PYGuide	Python reference with verified outputs

Author

Serhat Mercan — SAP BTP & AI Technical Lead | Generative AI for SAP | ABAP & SAP Fiori/UI5

• LinkedIn: serhat-mercan
• E-mail: serhatmercan94@gmail.com
• GitHub: serhatmercan

License

Released under the MIT License.

Scope: the MIT licence covers this repository's own examples, notes and documentation. It grants no rights over SAP-owned names, APIs, artifacts, data models or other intellectual property referenced by the examples — those remain SAP's, and being visible in an SAP system does not make them redistributable.