12.2 एक कॉलमने ग्रुप (शहरनिहाय विक्री)

By Ravindra Bagale Last updated: 31 October 2026

का (Why). एक-कॉलम ग्रुप्स “शहर / चॅनेल / एजंट निहाय” उत्तर देतात.

काय (What). एक कॉलम GROUP BY + मापांवर aggregates.

कसं (How). SELECT city, COUNT(*), SUM(amount_inr) FROM orders GROUP BY city;

पायऱ्या

उदाहरण 1 · dataset: interview_mini

SELECT channel, COUNT(*) AS n,
       ROUND(SUM(amount),2) AS total
FROM sales
GROUP BY channel
ORDER BY total DESC;

Output

Meaning. NULL channel सुद्धा वेगळा ग्रुप बनतो.

Ravindra Bagale's Tip

NULL group key = its own group — expect a blank channel row.