University case study erd problem essay

University case study erd problem essay

Question 6 Explain the distinctions among the terms primary key, candidate key, and Superkey : A superkey is any set of attributes such that the values of the attributes taken together uniquely identify one entity in the entity set. Draw an E-R diagram for this database. The distribution centers keep the following information about each shipment the date, an identification number of the product shipped, an identification number of the dealer that receives the shipment. Casual Customers must pay a deposit for an estimated time of rental, unless they wish to pay by Credit card. For example, a student can have more than one mobile number, email address, etc. In the ER diagram the relationship between two strong entity set shown by using a diamond symbol. The relationship between one strong and a weak entity set shown by using the double diamond symbol.

All major credit cards care accepted. Question 3 A database is to be designed for a Car Rental Co. Ford keeps the following information about the flow and cost data for all distribution centers to dealer channels: distribution center identification number, dealer identification number, product identification number, the number of miles between each distribution center and its dealers using the road network, the quantity of products being shipped and the dollar value of the shipment.

The college provides a number of module, each being characterized by its Code, title, Credit value, module leader, teaching staff and the department they come from.

Therefore the data about garages to be kept in the database includes garage names, addresses, range of Services and the like.

Different types of cardinal relationships are: One-to-One Relationships.

er diagram case study pdf

Question 5 A relational database is to be designed for a medium sized company dealing with industrial applications of Computers.

Rohit has recorded the yield of each livestock classification group during the last ten years.

Database case study examples with solutions

Instead, it should be derived from the DOB of that employee. All attributes have their separate values. Maintaining a well organized database of information, will contribute to achieving this goal. Example of Entities: A university may have some departments. These customers may also book in advance a particular car. The records consist of the year, yield, sales, price of the crop and the amount of money earned. Entities are represented by their properties, which also called attributes. It is the company policy not to keep any car for a period exceeding one year. CRC maintains reasonably stable client base. On admission, the personal details of every patient are recorded.

For example, a student's contact number. Students are free to choose any module they wish but the following rules must be observed some modules require pre-requisites modules and some degree programmes have compulsory modules.

The line connecting the weak entity set for identifying relationship is double. Some garages require payments immediately after a repair has been made, with others CRC has made arrangements for Credit facilities.

Question 2 A general hospital consists of a number of specialized wards such as Maternity, Paediatry, Oncology, etc.

entity relationship diagram pdf
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ERD CASE STUDIES