Question 1 Substitution Variable: What is a "substitution" variable and how might it be used in a SQL statement?
Question 2 Subquery Concepts: Define a subquery and discuss its use in SQL. Provide examples of utilizing subqueries to solve a business problem.
Question 3 Database Transactions: What does it mean to say that a transaction has "ACID" qualities? Why is it important to properly design transactions and how does it affect the database/information system?