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

Assignment Help:

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.


Related Discussions:- Draw an er diagram with primary key for a farm

Project, I have a small project that contains 3 deliverable s. I have done ...

I have a small project that contains 3 deliverable s. I have done the first one and I would like you to help me with second one

Information infrasctructure., what factors might influence a company to out...

what factors might influence a company to outsource its IT infrascture.

Help, #questiononsider the following relation: CAR_SALE =(CAR_ID,oPTION_TYP...

#questiononsider the following relation: CAR_SALE =(CAR_ID,oPTION_TYPE, Option_listpreice, Sale_date, Option_discountedprice)..

Index and tree structure, Index And Tree Structure Let us talk about th...

Index And Tree Structure Let us talk about the data structure that is used for creating indexes. Can we use Binary Search Tree (BST) as Indexes? Let us initial reconsider

Support by adding indexes, Support by Adding Indexes Multiple indexes c...

Support by Adding Indexes Multiple indexes can be used to access a data file by multiple access paths. In such a scheme only single copy of the data is consider, only the numbe

Define the two phase locking protocol, Define the Two Phase Locking Protoco...

Define the Two Phase Locking Protocol This is a protocol that is used to make sure serializability of transactions. This protocol needs that every transaction issue lock and u

File organisation and its types, File Organisation And Its Types  Just ...

File Organisation And Its Types  Just as arrays, trees, lists and other data structures are used to execute data Organisation in main memory, a number of planning's are used to

Load - unload utilities, These permit the user to unload a database or part...

These permit the user to unload a database or parts of a database and reload the data on the similar machine, or on another machine in a dissimilar location. This can be useful in

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd