Draw an er diagram with primary key for a farm, Database Management System

Draw an ER diagram that represents the information described below. Show all entity sets, relationship sets, primary keys, and the mapping cardinality of the relationship sets.

"Farmers own one or more sections of land, on which one or many types of grain (e.g., canola, rye, wheat, etc.) may be grown. The grain type can be uniquely identified by its grain ID. As each land section is owned by a single farmer, the farmer knows the amount of each type of grain (measured in tonnes) that is grown in each land section. Based on this information, the farmer can compute the total amount of grains grown in each land section. Each farmer has a name (consists of first name, middle initial, and last name) as well as a unique farmer ID, and may have several contact phone numbers.

When the grains are harvested, each farmer makes a contract to sell some of his grain to a specific grain pool (distribution centre). There are many pools, but each pool handles only one specific type of grain. The price per tonne is constant for each individual pool. There may be multiple pools handling the same type of grain. Normally, a farmer has a contract with a specific pool for a specific amount of a specific type of grain handled by that pool. However, a farmer may have contracts with many pools. Each pool then contracts with a business to sell a specific quantity of grain to that business at an agreed-upon price. This price may vary from contract to contract. A pool may have any number of contracts with any number of businesses, including multiple contracts with the same business. Each pool must maintain the total amount of grain that it has purchased from all of its farmers and the total amount of grain that it has contracted to sell."

Hint: For this question, you may assume the following:

(a) Each land section can be uniquely identified by its section ID. Given a section ID, one can easily find the dimension of the land section.

(b)  One or many types of grain may be grown on the same land section, and the same type of grain may be grown on different land sections.

(c)  Given a grain ID, one can identify the name of the grain type (e.g., canola, rye, wheat, etc.).

(d)  A grain pool (distribution centre) can be uniquely identified by its pool ID.

(e)  Several farmers may have contracts with the same pool.

(f)  A business can be uniquely identified by its business ID.

Posted Date: 2/28/2013 6:17:32 AM | Location : United States







Related Discussions:- Draw an er diagram with primary key for a farm, Assignment Help, Ask Question on Draw an er diagram with primary key for a farm, Get Answer, Expert's Help, Draw an er diagram with primary key for a farm Discussions

Write discussion on Draw an er diagram with primary key for a farm
Your posts are moderated
Related Questions
Explain trivial dependency? Functional dependency of the form α ->β. is trivial if α C β. Trivial functional dependencies are satisfied by all the relations.

Events4Fun is an event management company in Europe with branches in South America as well. The company is well-known for its efficiency, good-quality services, and affordable char

Explain the concepts of relational data model? Relational Data Model - The relational model was first introduced through Prof. E.F. Codd of the IBM Research in the year 1970

what would go in order patient#, patient name, patien address, surgeon#, surgeon name, surgery date, surgery type, drug admin

Q. State the Technique for converting a state diagram to code. i) Identify the major control path. Starting with first state, find the path from diagram that corresponds

Name the various privileges in SQL? A) Delete B) Select C) Insert D) Update

Explain ER Relationship model? An entity-relationship model (ERM): An entity-relationship model (ERM) is an abstract theoretical illustration of structured data. Entity-relatio

Replicating Data One approach that may support efficient access to dissimilar applications as above may be to give access to every of the applications from dissimilar replicate

What is a recovery scheme? An integral part of a database system is a recovery scheme that can restore the database to the reliable state that existed before the failure.

I need an ERD created for any original database(can be on anything). It needs to be 3NF. I then need all the CREATE STATEMENTS, INSERT STATEMENTS(anything you can think of as long