fix(week10): correct WARN-severity guidance + add INNER JOIN hint#3
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Two student-facing fixes found by building the assignment against live
Azure Postgres:
- Singular-test stub claimed severity is "set in dbt_project.yml". The
template ships no dbt_project.yml (students dbt init their own), and a
project-level severity would silently downgrade the not_null /
unique_combination PK tests. Point students at an inline
{{ config(severity='warn') }} instead.
- Mart stub said only "join trips to zones". A pickup_location_id with no
matching zone (e.g. 999) becomes NULL borough under a LEFT JOIN and fails
the not_null PK test. Tell students to INNER JOIN so pickup_borough stays
non-null and the mart lands at the rubric's 184 rows.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PLwBsooLgWEkUqJYVK7FsU
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What
Two small, student-facing scaffold fixes surfaced by building the Week 10 assignment end-to-end against the live
nyc_taxitables on Azure Postgres (the static autograder passes but never runs dbt, so it missed these).1. Misleading WARN-severity comment (
tests/assert_avg_tip_pct_within_bounds.sql)The stub told students the test is "intentionally set to WARN severity in dbt_project.yml." But the template ships no
dbt_project.yml(studentsdbt inittheir own), and a project-level severity would silently downgrade theirnot_null/unique_combinationprimary-key tests to warnings too. Now points at an inline{{ config(severity='warn') }}.2. Missing INNER JOIN hint (
models/marts/fct_daily_borough_stats.sql)A handful of trips have a
pickup_location_idwith no matching zone (e.g.999, 5 trips). Under aLEFT JOINthose becomeNULLborough and fail thenot_nullPK test, and the mart lands at 186 rows instead of the rubric's 184. The stub now tells students to use anINNER JOIN.Verification
A correct solution built on this template now runs
dbt build= PASS=12 WARN=1 ERROR=0, mart = 184 rows, singular test = WARN 3 (Unknown bucket) — matchingweek_10__assignment_rubric.mdexactly.Not included
No
dbt buildCI added here: the scaffold is intentionally stubs-only and cannot build. The real regression guard is building the answer key in CI (asnyc-taxi-dbt-referencealready does) — flagged separately.🤖 Generated with Claude Code