Skip to main content
SQL-BASICS5 MIN READ

Sensor Alerts: Before and After the Right Time Grain

Align selected time fields with the GROUP BY grain in an aggregate query.

Ava needs hourly average freezer temperature by device, but the before query tries to display raw reading time next to an average. Facilities operations desk with an analyst looking at a freezer monitoring dashboard, scattered sensor cards and a jagged temperature line shown as abstract visual shapes, clean control-room setting with cool lighting and open overlay space, no text, words, letters, numerals, logos. Before scene: many individual sensor readings are mixed with a single average, and a raw reading timestamp is treated as if it represents the whole group. Before: one raw timestamp is asked to represent many readings. https://oylytksvdaqzqcpcfhxp.supabase.co/storage/v1/object/public/omie-images/nugget-scenes/9d02d833-e963-4b20-8c85-aa36954b2c70-6.png…

Read the full lesson

Sign up free — one personalized lesson every day, matched to your role and goals.

Already have an account? Sign in

← Back to library