12. GROUP BY: प्रत्येक ग्रुपसाठी एक रो
12.3 दोन कॉलमने ग्रुप (शहर आणि प्रॉडक्ट)
का (Why). दोन कीज “शहर आणि प्रॉडक्ट” स्टाइल pivots.
काय (What). GROUP BY city, product_id (नंतर join ने नावे).
कसं (How). Aggregate नसलेला प्रत्येक कॉलम GROUP BY मध्ये लिहा.
पायऱ्या
- city आणि product_id.
- city मग sales.
- एक शहर ब्लॉक वाचा.
उदाहरणे
उदाहरण 1 · dataset: raja_coffee
SELECT city, product_id,
COUNT(*) AS orders,
ROUND(SUM(amount_inr),2) AS sales_inr
FROM orders
GROUP BY city, product_id
ORDER BY city, sales_inr DESC;Output
| city | product_id | orders | sales_inr |
|---|---|---|---|
| Goa | 102 | 1 | 890.0 |
| Goa | 103 | 1 | 360.0 |
| Goa | 104 | 1 | 350.0 |
| Kolhapur | 103 | 1 | 900.0 |
| Kolhapur | 102 | 1 | 890.0 |
| Kolhapur | 105 | 1 | 620.0 |
| Mumbai | 105 | 1 | 930.0 |
| Mumbai | 101 | 1 | 840.0 |
| Mumbai | 103 | 1 | 720.0 |
| Nashik | 103 | 1 | 1080.0 |
| Nashik | 102 | 1 | 890.0 |
| Nashik | 104 | 1 | 350.0 |
| Pune | 102 | 2 | 2670.0 |
| Pune | 101 | 2 | 2520.0 |
| Pune | 104 | 3 | 2100.0 |
| Pune | 103 | 2 | 1260.0 |
| Pune | 105 | 1 | 620.0 |
| Solapur | 101 | 1 | 420.0 |
| Solapur | 105 | 1 | 310.0 |
Meaning. प्रत्येक शहर+प्रॉडक्ट जोडीसाठी एक रो.
Ravindra Bagale's Tip
More GROUP BY columns ⇒ more (finer) rows in the result.
Ravindra Bagale's Tip – मराठी
जास्त GROUP BY कॉलम ⇒ निकालात जास्त (बारीक) रो.
Ravindra Bagale's Tip – हिंदी
ज़्यादा GROUP BY कॉलम ⇒ नतीजे में ज़्यादा (बारीक) पंक्तियाँ।