📝 What You’ll Learn

• What the AND operator does
• Syntax and logic
• Combining multiple conditions
• Real-world examples
• Common mistakes

🔍 What Is the AND Operator?

The AND operator is used in SQL to combine multiple conditions in a WHERE clause. All conditions joined by AND must be true for a row to be included in the result.

🧱 Basic Syntax

SELECT column1, column2
FROM table_name
WHERE condition1 AND condition2;

This means:

Only return rows where both condition1 and condition2 are true.

🔄 Example: Filtering with AND

Suppose we have a table employees with columns: name, age, department.

SELECT name
FROM employees
WHERE age > 30 AND department = 'Sales';

✅ This query returns employees who are over 30 and work in the Sales department.

⚙️ More Examples

Find users from USA who are active

SELECT name
FROM users
WHERE country = 'USA' AND status = 'active';

Get products in stock and under $50

SELECT product_name, price
FROM products
WHERE stock > 0 AND price < 50;

🧠 Common Mistakes

• ❌ Forgetting parentheses when mixing AND with OR:

  -- Can lead to unexpected results:
  SELECT * FROM users WHERE country = 'USA' OR country = 'UK' AND active = 1;
  
  -- ✅ Better:
  SELECT * FROM users WHERE (country = 'USA' OR country = 'UK') AND active = 1;
  

• ❌ Using AND when you meant OR, or vice versa — read your logic carefully!

📘 Recap

• AND combines multiple conditions and all must be true
• Helps you write precise and powerful filters
• Use parentheses when combining with OR for clarity
• Always test your conditions for accuracy