Consider the relations:
PROJECT(proj#,proj_name,chief_architect)
EMPLOYEE(emp#,emp_name)
ASSIGNED(proj#,emp#)
Use relational algebra to express the subsequent queries:
(i) Get details of employees working on project COMP33.
(ii) Get the employee number of employees who work on all projects.
(iii) Get details of project on which employee with name ‘RAM' is working.
Ans:(i) EMPLOYEE ∏Emp#(σproject#='comp33'(ASSIGNED))
(ii) ∏Emp#(EMPLOYEE)-(ASSIGNED ÷∏project#(PROJECT))
(iii) PROJECT (∏project#(σEmp_name='RAM'(EMPLOYEE) ASSIGNED))