Question

Use Relational Algebra for the question (Use pi and sigma commands)

You are given the following relational schema  

Employee(ename, street, city, salary, deductions)

Branch(ename, branch-name)

Deputation(ename, org-name, returning date)

Project (pno, pname,city)

Works(ename, pname,hours)

Write relational algebra expressions to answer the following queries:

A. Retrieve the total salary drawn and number of employees working in each branch.  

B. Find the number of employees deputed by each organization. Don’t include employees whose returning date is later than 15 July 2015.

C. Find the average salary drawn by employees deputed by each organization. Include those organizations which have employees having a minimum salary of 10000.

D. Display all the employee name, city they live in, along with the organization if deputed or the branch name for which they work.

E. Display the employee names who are working on all the projects in Delhi (project city).​

Answer 1

Answer:

C. Find the average salary drawn by employees deputed by each organization. Include those organizations which have employees having a minimum salary of 10000.