Question 1: An E/R diagram when converted to relations gives rise to the following relations: R(A,B,C) S(A,D) T(D,F,G) You may assume that the same symbols refer to the same attribute and different symbols refer to different attributes (e.g., the attributes a in the relations R, S, and T are the same). Your task is to reverse-engineer the E/R diagram from these relations, in other words, what E/R diagram could have produced these relations?

Question 2: Draw an E/R diagram to model project groups in CSC430. Keep in mind that each enrolled student (identified by a SID) can work at most one project. students work in groups of no moer than 3 members. each group works on one project. Each project is identified uniquely by its name and can have more han one group working on it. Be sure to identify all the appropriate multiplicity and referential integrity constraints in the diagram. Indicate key attributes in each entity set. (15 points)

Question 3: Consider the relational database whose schema is shown below: EMPLOYEE (Emp-ID, E-name, gender, DOB, disability, health-status) COMPANY (company-name, tax-ID, company-status) Lives (Emp-ID, street, city) Works (Emp-ID, company-name, salary) Located-in (company-name, city) The primary key for each relation is denoted by the underlined attribute.

1. Write the DDL commands to create a database called LA-NGO-Database. (7 points)

2. Write the following queries in Relational Algebra: (8 points)

a. List the names of all female employees, who work for the Ruston Bank (a unique company name in the database).

b. List all the companies who are in located-in the same city of the company Ruston Bank.

c. List the name of all employees who work for the Ruston Bank.

d. List the personal information of name, street, and city of all employees who work for the Ruston Bank and earn more than $10,