Draw an entity-relationship diagram for the following case. The United Nations wants to develop a global database,
Question:
Draw an entity-relationship diagram for the following case.
The United Nations wants to develop a global database, tracking countries, cities, and multinational companies. For each country, the UN wants to store its name, capital, population, and the name of its head of state. The UN assigns each city in the world a unique, global, numeric identifier. It also wants to record the city's name, the name of the city’s mayor (or chief executive), its population, and its size in square miles. Obviously, a city is associated with only one country. Each city has many employees. Each employee has an employee number unique to that city, plus a name and date of birth. Some employees of a city manage other employees of that city. Each city also has city-owned buildings. Each building a city owns has a type (fire station, police station, etc.) an address (its unique identifier), and the year it was built. Each multinational company has a globally unique identifier, a name, a president, and the year it was founded. Obviously, a country has many companies operating in it and, by definition, a multinational company can operate in more than one country. The UN wants to keep track of how much revenue each company generated each year in each country in which it operates.
This is an Example on how it should look like :
Systems analysis and design
ISBN: ?978-1118808177
5th edition
Authors: Alan Dennis, Barbara Haley Wixom, Roberta m. Roth