For these exercises, we use the Employees Database presented at the end of Chapter 1. Answer each question with a single SQL statement. Your query must work for any set of data in the Employees Database, not just the set of data we provide.

Find the names of all people who work in the Consulting department and who spend more than 20% of their time on the project with ID ADT4MFIA. Solve three ways: 1) using only WHERE-based join (i.e., no INNER/OUTER/CROSS JOIN), 2) using JOIN ON, and 3) using NATURAL JOIN whenever possible and JOIN ON otherwise.

24 Chapter I:Databasks projects projectd deparmenls code managerid subdeplof description startdate encdate revenue workson empore edi assignedime employeeld firstname lastname deplcode salary Figure 1.5: Schema for the Imployees Database