feat(rules): add W019 count-distinct-unbounded rule#29
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Pawansingh3889 merged 1 commit intoPawansingh3889:mainfrom Apr 26, 2026
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feat(rules): add W019 count-distinct-unbounded rule#29Pawansingh3889 merged 1 commit intoPawansingh3889:mainfrom
Pawansingh3889 merged 1 commit intoPawansingh3889:mainfrom
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Resolves Pawansingh3889#7. (Issue title says W017 but W017 is now leading-wildcard-like in v0.6.0; W019 is the next free ID before W020.) Warns on COUNT(DISTINCT col) without a WHERE, GROUP BY, or LIMIT in the same statement -- forces a full sort + distinct pass and is a frequent perf surprise on prod. - 'SELECT COUNT(DISTINCT user_id) FROM events;' -> fires - 'SELECT COUNT(DISTINCT user_id) FROM events WHERE event_date >= ...' -> passes - 'SELECT tenant_id, COUNT(DISTINCT user_id) FROM events GROUP BY tenant_id;' -> passes - 'SELECT COUNT(*) FROM events;' -> not flagged Updated: - sql_guard/rules/warnings.py: new CountDistinctUnbounded rule. - sql_guard/rules/__init__.py: registered in ALL_RULES. - tests/test_new_rules.py: 6 new test cases covering hit, WHERE, GROUP BY, LIMIT, whitespace handling, and plain COUNT non-firing. - tests/test_rules.py: bumped expected ALL_RULES count 32->33 and warning count 22->23. - CHANGELOG.md: Unreleased entry.
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Pawansingh3889
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🎉 second W-rule from you this week, nice work 👏 thanks for picking this back up after W017 got taken in v0.6.0. landing as W019 makes sense, and the TOP / FETCH NEXT bypass is exactly what the T-SQL crowd needs. subquery and CTE bodies still slip past, but that's a regex limitation. fine for now. squashing 🚀 |
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Apr 26, 2026
Single-rule patch release. W019 lands count-distinct-unbounded from PR #29 (mvanhorn). Bypass list recognises WHERE / GROUP BY / LIMIT plus T-SQL TOP / FETCH FIRST / FETCH NEXT. Surface counts refreshed: 38 rules (33 SQL + 5 Python), 149 tests. Trusted Publishing will fire on the v0.6.1 tag push.
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Appreciate getting this rule in. |
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Resolves #7.
Warns on
COUNT(DISTINCT col)withoutWHERE,GROUP BY, orLIMITin the same statement. That pattern forces the engine into a full sort + distinct pass over the whole table, which is the perf surprise the issue flags.Behaviour
SELECT COUNT(DISTINCT user_id) FROM events;SELECT COUNT(DISTINCT user_id) FROM events WHERE event_date >= '2024-01-01';SELECT tenant_id, COUNT(DISTINCT user_id) FROM events GROUP BY tenant_id;SELECT COUNT(DISTINCT user_id) FROM events LIMIT 1;SELECT COUNT(*) FROM events;/SELECT COUNT(user_id) FROM events;Whitespace inside the call (
COUNT ( DISTINCT user_id)) is tolerated.Tests
6 new cases in
tests/test_new_rules.pycovering the matrix above, plus the registry-count tests intests/test_rules.pywere bumped from 22 -> 23 warnings (32 -> 33 total).pytest tests/is 127 passed, 1 skipped.