Write the following queries in SQL

1. Consider the following database schema describing students enrolled in sections of classes at a university. student (sid*, sname, sex, age, year, gpa) [Year is a number between 1 and 5). dept(dname*, numphds) prof(pname*, dname) course(cno*, cname, dname*) (Course numbers are unique within departments.] major(dname*, sid*) section(dname*, cno*, sectno*, pname) (Associates an instructor to a section.] enroll(sid*, grade, dname*, cno*, sectno*) (Associates students to sections. (8) Give the names of each professor who has in one of his/her classes a student older than 50. List each professor at most once, in alphabetical order. (h) Show the dname, cno and sectno of all course sections together with the total number of students enrolled in the section. Order the output in decreasing order of popularity. (1) Find all information about students who are not enrolled in any classes. G) List all pairs of professor names where the two professors teach the same course in the same department. Don't repeat any pairs