Tricky~20min
The Batch That Passed Without Being Tested
7 production batches are marked qa_status = passed with zero rows in qa_test_results — nobody actually ran a test before signing off. 13 more batches also show zero test rows and a passed status, but those are on the low_risk_repackaging line, which is exempt from per-test logging by policy — not a problem.
Tables you'll query
batchesqa_test_results
What you'll learn
JOINsNULL Handling