SQL Programming Advanced Quiz 2

1. What is a window function? Write a query to calculate running total of sales.

2. Explain the concept of transactions and ACID properties.

3. Write a SQL query to delete records older than 30 days from a "Logs" table.

4. What is a stored procedure? Write a simple stored procedure to get order history by customer ID.

5. What is a trigger? Write a trigger to update "LastUpdated" timestamp on record modification.

6. What is a composite key?

7. Explain the difference between UNION and UNION ALL.

8. Write a SQL query to find duplicate emails in a "Users" table.

9. How do you select the second highest salary from "employees"?

10. Write a SQL query to update employee salaries by 10%.