Write the following inserts, deletes or updates in SQL, using the university schema.
a. Increase the salary of each instructor in the Comp. Sci. department by 10%.
b. Delete all courses that have never been offered (that is, do not occur in the section relation).
c. Insert every student whose tot_cred attribute is greater than 100 as an instructor in the same department, with a salary of $10,000.