Consider the relational diagram below.
Employee(fname, minit, lname, ssn, bdate, address, sex, salary, superssn, dno)
Department(dname, dnumber, mgrssn, mgrstartdate)
Project(pname, pnumber, plocation, dnum)
Works_on(essn, pno, hours)
Dependent(essn, dependent_name, sex, bdate, relationship)
Express the following queries with relational algebra and multiple relation analysis. (Express the following
queries either in relational algebra or tuple relational.)
(a) Return the average salary of all female employees.
(b) Bring back the names of all employees working on each project.
(c) Bring back the names of all employees who did not work on any project.