Reject Duplicate Key

Review ask

As a clinical trial statistician or programmer, challenge anything in this benchmark: describe a problem in Comments, or propose a fix with the Edit button on any source file.

Task: Is this a specification error a study team could realistically make, and should the build stop on it rather than continue?
Inputs: Do they trigger the failure for the reason the summary gives?
Expected failure: Is this the right error, raised at the right point, and would it tell the programmer what to fix?

The other tabs beside Comments are background for assessment, not under review.

Summary

EditUnder reviewWhat this benchmark means

README.md

Goal: build one record per subject carrying the actual treatment for period 01 (TRT01A).

Input: demographics records plus analysis-subject records carrying a treatment (TRT01A).

Variables:

TRT01A would contain the treatment from the analysis-subject record for the same subject.

When more than one analysis-subject record shares one subject's identifiers, nothing says which treatment applies. Taking either one would report a treatment the study data does not single out, so the run is rejected with no artifact accepted.

How to fix

Reconcile the analysis-subject source so each subject has one supported treatment. If multiple records are legitimate, add a field that expresses the choice, such as an effective timestamp, and select by it explicitly:

intermediates:
  - id: ADSL_LOOKUP
    dataset: ADSL_RAW
    order_by: [ADSL_RAW.EFFECTIVEDTC]
    keep: last

Do not use file order or treatment text as a substitute for a study rule.

Expected failure

Editthe run is rejected; no artifact is accepted

expected/error.yaml

phase: join
condition: multiple_matches
requirement: REQ-0127

expected/error.yaml

phase: join
condition: multiple_matches
spec_paths:
  - columns.TRT01A.derivation.source
requirement: REQ-0127
context:
  intermediate: intermediate(ADSL_RAW)
  dataset: ADSL_RAW
  key:
    - STUDYID
    - USUBJID
  intermediate_key:
    STUDYID: PILOT7
    USUBJID: P7-701
  match_count: 2
  keys:
    - STUDYID: PILOT7
      USUBJID: P7-701

YAML specification

1 spec file

spec.yaml

Edit29 lines

1schema_version: "1.0"2domain: ADSL3keys: [STUDYID, USUBJID]4input:5  DM: input/dm.csv6  ADSL_RAW: input/adsl_raw.csv7base: DM89output:10  path: adsl.csv11  columns: [STUDYID, USUBJID, TRT01A]1213columns:14  - name: STUDYID15    type: str16    label: Study Identifier17    derivation: DM.STUDYID1819  - name: USUBJID20    type: str21    label: Unique Subject Identifier22    derivation: DM.USUBJID2324  # Matched on the output keys, STUDYID and USUBJID. With no order_by/keep,25  # nothing chooses between two ADSL_RAW records for the same subject.26  - name: TRT01A27    type: str28    label: Actual Treatment for Period 0129    derivation: ADSL_RAW.TRT01A

Inputs

Under review2 source files

input/adsl_raw.csv

Edit2 rows

input/adsl_raw.csv
STUDYID	USUBJID	TRT01A
PILOT7		Pembrolizumab
PILOT7		Placebo

input/dm.csv

Edit1 row

input/dm.csv
STUDYID	USUBJID
PILOT7

Unexpected Output

Under reviewNo artifact is produced

No fixture files in this directory.

Shaded columns are derived— = missing value

Comments and assessment materials

Dataset Name	Variable Name	Variable Label	Type	Computational Method	Origin
ADSL	STUDYID	Study Identifier	character	Copy value from DM.STUDYID.	Predecessor
ADSL	USUBJID	Unique Subject Identifier	character	Copy value from DM.USUBJID.	Predecessor
ADSL	TRT01A	Actual Treatment for Period 01	character	Copy value from ADSL_RAW.TRT01A.	Predecessor

Version	Date	Author	Description
1.3	2026-09-29	yamaa docs build	Show study codelist names, external dictionaries, and ISO 8601 formats in variable rows; list the document's codelist values and metadata
1.2	2026-09-29	yamaa docs build	Classify ADaM copies from a declared input as Predecessor and recodes as Derived, and SDTM recodes of locally derived columns as Derived
1.1	2026-09-29	yamaa docs build	Resolve lookups into the donor record they select, and give every derivation shape a plain-language rule instead of its raw YAML
1.0		yamaa docs build	Initial generation from spec.yaml

How to fix

input/adsl_raw.csv

input/dm.csv

Comments

Mapping spec