📝 What You’ll Learn

• What the NOT operator does
• Syntax and structure
• How to negate conditions
• Real-world examples
• Common usage notes

❓ What Is the NOT Operator?

The NOT operator is used in SQL to negate a condition—it returns rows where the condition is false.

Think of it as flipping the logic:

NOT TRUE → FALSE
NOT FALSE → TRUE

🧱 Basic Syntax

SELECT column1, column2
FROM table_name
WHERE NOT condition;

You can also use NOT with logical operators like IN, BETWEEN, LIKE, etc.

🔄 Example: Using NOT

Get all users who are not from the USA

SELECT name
FROM users
WHERE NOT country = 'USA';

✅ This returns users from countries other than the USA.

🧪 More Examples

Products not in stock

SELECT product_name
FROM products
WHERE NOT stock > 0;

Employees not in Sales or HR

SELECT name, department
FROM employees
WHERE department NOT IN ('Sales', 'HR');

Customers not from cities starting with 'S'

SELECT name
FROM customers
WHERE city NOT LIKE 'S%';

⚠️ Usage Notes

• NOT flips the result of the condition that follows it
• Use parentheses to group logic when combining with AND or OR
• Be mindful with NULLs—NOT NULL means the value must exist

📘 Recap

• The NOT operator inverts conditions
• Useful for filtering everything except a certain condition
• Combine with other operators like IN, LIKE, BETWEEN
• Always check your logic to avoid unexpected results