Information Science Department ISC 321: Database Systems Summer 2016 Homework #2 Due

Kuwait University College of Computing Sciences & Engineering

Information Science Department ISC 321: Database Systems Summer 2016 Homework #2 due: 12/6/2016

1. Talabat.com is a Kuwaiti online food delivery web site and mobile app. It has been recently sold to a German e-commerce company for 50 million KD. You are required to design the ER diagram of the DB system of Talabat.com based on the following information:

 The DB should contain information about the users who have accounts with the web site. Each user has a name, a unique user id, a unique e-mail, a password, a date of birth and an address that consist of the block, street and house numbers.  Each user live in one area that has a unique area name and a governorate that it belongs to.  Information about the orders made are stored in the DB system. Each order has a unique order number and a date when the order was made.  Each order is made to a restaurant. Each restaurant has a unique restaurant id, a name, a type of food and an address that consist of an area, a block number, a street number and a house number.  Each restaurant has many menu items. Each menu item has a unique item id, an item name and a description.  Each restaurant delivers to certain areas in the country. Each area is delivered to by many restaurants.  Finally, each order contains a number of menu items. The quantity of each item should be stored for each order.

Create the ER diagram for this DB system.

2. Projects Inc., is an engineering firm. A database is required to keep track of all employees, assigned projects and departments in which they work.

- Every employee has a unique number assigned by the firm, a name, and date of birth. If an employee is married to another employee of the firm, the data of the marriage and who is married to whom must be stored; however, no record of marriage is required if an employee’s spouse is not also an employee. Each employee has a job title. Each employee does only one type of job at a time, and we only need to retain information about an employee’s current job. - There are many different departments in the firm, each with a unique name. An employee can report to only one department. Each department has a phone number. - To procure various types of equipment, each department deals with many vendors. A vendor typically supplies equipment to many departments. We Kuwait University College of Computing Sciences & Engineering

need to store the name and address of each vendor and the date of the last meeting between a department and a vendor. - Many employees can work on a project. An employee can work on many projects, but can only be assigned to at most one project in a given city. For each city, we are interested in its state and population. - Projects are distinguished by project numbers and we must store the estimated cost of each project.

Create the ER diagram for the database.

3. Suppose you are given the following requirements for a simple database for the National Hockey League (NHL): - The NHL has many teams, - Each team has a name, a city, a coach, a captain, and a set of players, - Each player belongs to only one team, - Each player has a name, a position (such as left wing or goalie), a skill level, and a set of injury records, - Ateam captain is also a player, - A game is played between two teams (referred to as host_team and guest_team) and has a date (such as May 11th, 1999) and a score (such as 4 to 2). Construct a clean and concise ER diagram for the NHL database.