Database: Relational Model and Code

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GeRard ryan relational database assignment

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GeRard ryan relational database assignment

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Contents
Introduction- 2 -
Description of Assignment- 2 -
Problems & Solutions- 4 -
Normalisation- 5 -
Data dictionary- 0 -
Relationships between each Table- 5 -
Database Tables- 6 -

Introduction
Description of Assignment
The company I have decided to base this assignment on is a fictional one that is a DVD/ Games rental outlet. They rent and sell DVD’s and games both old and the new company is a small business and employees two full-time and two part-time staff. The company orders its supplies from local and international suppliers so they need to keep records on file. At present they store these files in a filing cabinet, this causes many problems with the records and many files are either lost or damaged. The use of a relationship database will save the company a lot of paper work, the other advantages of using a database are that you can access the information with a simple query. It can provide valuable information by looking at database records and how data has changed over time, you can also track important trends, such as which product is most popular with your customers, which can make your business more competitive.They areinexpensive and smaller businesses find them to be a good way of cutting costs without cutting quality, converting from paper files to a database system can be difficult and requires a good level of knowledge of the system before attempting to transfer any files to a database.

Planning of Assignment
To create the database I will first have to create a plan of how many tables to put into it e.g. a staff table, staff roster, Product table, Order Table, Rental Table, and Supplier Table. In laying out the plan for this assignment I had to decide what tables would have a relationship, the following are the relationships I created with a brief explanation included: 1) The staff code has a relationship with the roster table, because one staff member can have many rosters. 2) The product and rental will have the most relationships. The rental code, supplier code, and order code all have relationships in the product table following the one to many rule. 3) The relationships in the rental include the roster code, customer code and product code. 4) The other tables containing relationships are the order table with the refund table.

By designing the database in this way it insures that the data in the tables with relationships cannot be changed.

This assignment covers one working week in the company showing how the company is run and how by creating this database it will help the company run the day to day tasks more efficiently and securely.

Problems & Solutions

Problem 1
At present the company keeps all their files in hard copy and it causes important files to be misplaced or lost. Solution 1
By designing a relational database it will reduce the amount of hard copies and I some cases it can eliminate the need for any paperwork. Problem 2
The method that the company uses to back is very insecure and causes file to be misplaced. Solution 2
With a database the customer information is kept in one place and it is an easy and safe way of make a backup of all the files. Problem 3
The current system provides very poor security in the company as all the staff can easily view the customer’s personal information. Solution 3
The database provides good security and can be set up so that only a staff member that is given a password can access. Problem 4
It is hard for the company to determine which of the products in the store a most popular. This makes it hard to decide how much in each product such be ordered each week. This also can cause them to over order unpopular stock which they may find hard to sell and end...
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