SELECT-JOIN-GROUP Pocket Deck
Recall the core checks for a basic joined aggregate query.
battlecard comparison What is the practical reading order for a joined aggregate query? FROM/JOIN -> WHERE -> GROUP BY -> HAVING -> SELECT -> ORDER BY. The written order starts with SELECT, but debugging starts with source rows. Pipeline JOIN before GROUP BY vs GROUP BY before JOIN Protect the metric grain before SUM or COUNT sees duplicated rows. I added DISTINCT, so the duplicate problem is fixed. Say this DISTINCT only removes duplicate output rows. If SUM saw duplicated source rows, the total is still wrong. Cosmetic deduping can hide a grain bug. It redirects the review to row…
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