Regional Labs is a company that conducts research and development work on a contract basis for other companies and organizations. Figure 2-31 shows data that Regional Labs collects about projects and the employees assigned to them. This data is stored in a relation (table) named PROJECT: PROJECT (ProjectID, EmployeeName, EmployeeSalary) Assuming that all functional dependencies are apparent in this data, which of the following are true? ProjectID → EmployeeName ProjectID → EmployeeSalary (ProjectID, EmployeeName) → EmployeeSalary EmployeeName → EmployeeSalary EmployeeSalary → ProjectID  EmployeeSalary → (ProjectID, EmployeeName

Implement a new independent entity phone in the Sakila database. Attributes and relationships are shown in the following diagram: The diagram uses Sakila naming conventions. Follow the Sakila conventions for your table and column names: All lower case Underscore separator between root and suffix Foreign keys have the same name as referenced primary key Write CREATE TABLE and ALTER TABLE statements that: Implement the entity as a new phone table. Implement the has relationships as foreign keys in the Sakila customer, staff, and store tables. Remove the existing phone column from the Sakila address table. Step 2 requires adding a foreign key constraint to an existing table. Ex: ALTER TABLE customer ADD FOREIGN KEY (phone_id) REFERENCES phone(phone_id) ON DELETE SET NULL ON UPDATE CASCADE; Specify data types as follows: phone_id, phone_number, and country_code have data type INT. phone_type has date type VARCHAR(12) and contains strings like 'Home', 'Mobile', and 'Other'. Apply…

What three situations make it necessary to make a substitute key instead of the main key of a relation?

create an ER table

A rental car company divides its cars into four categories: small, mid-size, full-size, and sport utility. The agency wishes to collect the following information from all vehicles: Vehicle, Make, Model, Year, and Color are all required. There are no distinguishing characteristics for any of the four vehicle classifications. Rents is a connection between the entity type vehicle and the entity type client. There is no one-to-one connection between any of the four vehicle types and any entity type. Would you think about making a supertype/subtype connection for this problem? If so, why or why not?

Indicate the changes (using the shorthand representation) that you would need to make to the original KimTay Pet Supplies database design to support the following requirements. There is no relationship between customers and sales reps. When a customer places an order, any sales rep can process the order and create the invoice. On the invoice, you need to identify both the customer placing the order and the sales rep responsible for the invoice. Draw an E-R diagram for the new design.

StayWell also rents out properties on a weekly basis to students attending summer school in the Seattle area. Design a database to meet the following requirements, using the shorthand representation and a diagram of your choice. For each student renter, list his or her number, first name, middle initial, last name, address, city, state, postal code, telephone number, and e-mail address. For each property, list the office number, property address, city, state, postal code, square footage, number of bedrooms, number of floors, maximum number of persons that can sleep in the unit, and the base weekly rate. For each rental agreement, list the renter number, first name, middle initial, last name, address, city, state, postal code, telephone number, start date of the rental, end date of the rental, and the weekly rental amount. The rental period is one or more weeks.

The following relations are part of a general store database: customer(custnum, custname, city, creditlimit) orders(ordernum, orderdate, filled, custnum) orderline(ordernum, productnum, quantity, salesprice) product(productnum, descr, producttype, msrp, onhand) Here is a sample data (assume there are more records)Using PROJECT, SELECT and JOIN, write the sequence of operations to answer each of the following questions: 1a. What are the names and customer numbers of customers who are from Mississauga? 1b.What are the names of products (descry) and product types of products purchased by customers from brapton?

Each relationship is mapped into a relation? true or false

Convert to relation schema