From the student table, classify each student by total credits earned. Return ID, name, tot_cred, and a computed column standing defined as: 'Senior' when tot_cred is 100 or more, 'Junior' when it is at least 60 (but under 100), 'Sophomore' when it is at least 30 (but under 60), and 'Freshman' otherwise.
Database schema
primary keyforeign keyarrow points to the referenced columndrag to pan