In The North Wind Database System:

Specifics

$1.$ In this activity you are going into a company as a recently hired database administrator, data architect, or data engineer. You are a business intelligence person with a good understanding of relational database design. You are the one responsible for the data. But there has been a bit of trouble.

$2.$ The more senior BI person was recruited away for a base salary of $$200,000$ at some other technical company and the data team needs you to jump into work mode right away. The person that was recruited away did not document the data system very well and the problem is that accounting and other departments rely on this information. You have the ERD and can run queries to figure out how the database is designed and what information is within the database.

$3.$ There are a wide variety of issues and problems that you need to provide answers to based on your understanding of the data system and the data that is contained in the system.

Tasks

The accounting department is reconciling a major financial disaster. There accounting software had a problem and did not import the data correctly for a portion of two quarters. They, accounting, need to know how much was billed during the months of July and August of $2016.$ Prepare a query for them that they can use to reconcile their books. Feel free to include any information that you think an accounting department would need to know relative to the data that is the entire data system. Provide your query and your rationale for its use as a source of truth for the reconciliation of the accounting system.