SQL AND / OR / NOT
Use AND, OR, and NOT to build complex filters in your WHERE clause.
🔹 How They Work
- AND — all conditions must be true
- OR — at least one condition is true
- NOT — reverses the condition (negation)
🔹 Examples
-- Both conditions must be true
SELECT * FROM employees
WHERE department = 'IT' AND salary > 60000;
-- Either condition can be true
SELECT * FROM employees
WHERE department = 'HR' OR salary > 70000;
-- Negate a condition
SELECT * FROM employees
WHERE NOT department = 'Sales';
-- Combine all
SELECT * FROM employees
WHERE (department = 'IT' OR department = 'HR') AND salary > 50000;🧠 Quick Recap
| Operator | Meaning | Example |
|---|---|---|
| AND | Both conditions true | WHERE dept = 'IT' AND salary > 60000 |
| OR | Either condition true | WHERE dept = 'HR' OR salary > 70000 |
| NOT | Negates condition | WHERE NOT dept = 'Sales' |
✅ Use these to filter data precisely and flexibly!