Post #2716

Now, let’s move to the next topic in SQL Roadmap ✍️SELECT WHERE This is the most important beginner topic 👇 🧠 1. SELECT Statement • SELECT is used to retrieve data from a table 👉 Basic Syntax SELECT column_name FROM table_name; 👉 Example SELECT name FROM employees; • ✔ Returns only the name column 👉 Select Multiple Columns SELECT name, salary FROM employees; 👉 Select All Columns SELECT * FROM employees; 🎯 2. WHERE Clause (Filtering Data) • WHERE is used to filter records based on conditions 👉 Syntax SELECT * FROM table_name WHERE condition; 👉 Example SELECT * FROM employees WHERE salary > 50000; ✔ Returns employees earning more than 50k ⚡ 3. Operators You Must Know 🔹 Comparison Operators • = (equal) • > (greater than) • < (less than) • >= , <= • != or <> (not equal) 🔹 Logical Operators • AND → both conditions true • OR → any condition true • NOT → reverse condition 👉 Example SELECT * FROM employees WHERE department = 'IT' AND salary > 50000; 💡 4. Real-Life Thinking Instead of memorizing, think like this: • 👉 “What data do I need?” • 👉 “From which table?” • 👉 “What condition?” Example: “Show all HR employees earning less than 40k” SELECT * FROM employees WHERE department = 'HR' AND salary < 40000; 🎯 5. Practice Tasks 1. Show all employees with salary > 30k 2. Show employees from IT department 3. Show employees with salary between 40k–80k 4. Display only names of HR employees 5. Combine conditions using AND / OR 🔥Practice Tasks Solution ✅ 1. Show all employees with salary > 30k SELECT * FROM employees WHERE salary > 30000; ✅ 2. Show employees from IT department SELECT * FROM employees WHERE department = 'IT'; ✅ 3. Show employees with salary between 40k–80k SELECT * FROM employees WHERE salary BETWEEN 40000 AND 80000; • 👉 Alternative: SELECT * FROM employees WHERE salary >= 40000 AND salary <= 80000; ✅ 4. Display only names of HR employees SELECT name FROM employees WHERE department = 'HR'; ✅ 5. Combine conditions using AND / OR SELECT * FROM employees WHERE department = 'IT' AND salary > 50000; • 👉 OR example: SELECT * FROM employees WHERE department = 'HR' OR salary < 30000; ⚡ Double Tap ❤️ For More