4. WHERE: Keep Only the Rows You Need
4.4 AND, OR and NOT — Combine Conditions Safely
Why. Real filters need more than one condition.
What. AND = all must match. OR = any may match. NOT = reverse a condition.
How. Use parentheses when you mix AND and OR.
Steps
- Pune AND amount >= 800.
- Pune OR Mumbai.
- NOT city = 'Pune'.
Examples
Example 1 · dataset: raja_coffee
SELECT order_id, city, amount_inr
FROM orders
WHERE city = 'Pune' AND amount_inr >= 800
ORDER BY amount_inr DESC;Output
| order_id | city | amount_inr |
|---|---|---|
| 1016 | Pune | 1780.0 |
| 1013 | Pune | 1680.0 |
| 1004 | Pune | 1050.0 |
| 1006 | Pune | 890.0 |
| 1001 | Pune | 840.0 |
Meaning. Both conditions true: Pune and large amount.
Ravindra Bagale's Tip
When OR surprises you with too many rows, check parentheses.
Ravindra Bagale's Tip – मराठी
OR ने खूप रो आले तर कंस तपासा.
Ravindra Bagale's Tip – हिंदी
OR से बहुत पंक्तियाँ आएँ तो कोष्ठक जाँचें।