SQL Programming Advanced Quiz 1

1. What is the difference between INNER JOIN and LEFT JOIN?

2. Write a SQL query to find the second highest salary from an "Employees" table.

3. Explain the concept of normalization. What are the different normal forms?

4. Write a SQL query to retrieve all employees who have the job title "Manager".

5. What is a subquery? Write a SQL query using a subquery to find products priced higher than the average price.

6. Write a SQL query to count the number of orders placed by each customer in an "Orders" table.

7. Explain the use of indexes in SQL. How do they improve query performance?

8. Write a SQL query to find customers who have not placed any orders.

9. What is a CTE (Common Table Expression)? Write a query using a CTE to calculate total sales per product.

10. Write a SQL query to retrieve the top 5 highest-paid employees.