Database design | Computer Science homework help

Develop a database with geographic and other information about the countries of the world. As a first step you need to design an ER diagram that captures relevant information about the countries of the world.

• A country has a number of attributes, including a name, area, population, and GDP. A country has also a capital city, which itself has a name, population, and geographical coordinates (latitude, longitude). With each country there can be several spoken languages and several predominant religions.

• Countries are located on continents, the latter having a name and area. Any two countries may have a border between them of a particular length.

• A city can be part of country, and can also be situated on an island, or at a lake, river, or sea. A lake has a name, area, maximal depth, and altitude; a river has a name, length, and can flow in or out of a lake, or into a sea; a sea has a name, (maximal) depth, and may be connected with another sea. An island has a name, area, and may be part of one or more countries.

Here are the specific tasks you have to address based on the above information:

(a) Design a conceptual database schema (i.e., an Entity-Relationship diagram) for the above scenario based on the given information. Be sure to indicate primary key attributes for each entity type! Also, indicate derived (computed, not stored) attributes, if any. For each relationship type, clearly specify the semantics of a relationship type using the (min,max) notation presented in class. Note that an edge without a (min,max) specification is assumed to have the default specification (0,∗). Use the modeling concepts discussed in class. You don’t have to specify the data types (domains) for the attributes.

(b) Identify (reasonable) constraints that you are unable to capture using the standard ER modeling constructs. Do not specify trivial domain constraints, e.g., “attribute X is a positive number”. Formulate these constraints in plain English. For each constraint, give a brief explanation why you need the constraint and why you cannot express it in the ER diagram, e.g., using cardinalities.

(c) Translate your ER schema into a relational schema: For each table, list all attributes. To specify the tables, use the following notation, i.e.,

tablenamei (attribute1i, . . . , attributeni) …

Plus the notation for foreign key constraints (where needed). You do not have to specify any integrity constraints other than foreign key constraints, nor the attribute domains for the tables.

Place your order
(550 words)

Approximate price: $22

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
$26
The price is based on these factors:
Academic level
Number of pages
Urgency
Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Read more

Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

Read more

Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.

Read more

Privacy policy

Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.

Read more

Fair-cooperation guarantee

By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.

Read more