Web design and development

Web Design and Development Computer programming assignment help

FEBRUARY 28, 2017 PROGRAMMING ASSIGNMENTS HELP help@programmingassignmentshelp.net

Introduction: Web Design and Development Assignment This is a database design for an online video DVD sales portal. DVD Sales owner wants to create a portal which can be used by customers to purchase DVDs online without visiting to DVD store. Customers can view the DVDs available for sale in store and choose as per their wish. Customers can add DVDs in shopping cart and purchase them at the same moment or at later stage as well.

At the same time, store owner can add more DVDs in store and remove the DVDs which are not available for sale. Store owner can also analyse the trend of DVD sale from portal as sales data will be stored in database of portal. Based on the user request patterns, DVDs can be recommended to customers.

We will design database using relational database system model, and it will normalized up to 3NF, taking into consideration the requirement as specified in the case study.

Task 1 Task 1.1 Traditional File Processing Environment Computer systems were used in early stage to process business records and produce information. They were faster and more accurate than manual systems. These computer systems stored groups of records in separate files, and so they were called file processing systems.

In a file processing systems, files are created department wise and designed specifically for those applications. Every department has to work on it with data processing staff, has to set policies or standards for the format and maintenance of its files.

Programs are dependent on the files and vice-versa, that is, if there is any change in physical format of the file, respective program also to be changed.

Common advantages and disadvantages of File Processing System are as below: Advantages

Disadvantages

Simple to use

Does not support concurrent user access

Less expensive

Limited to smaller set of data

Fulfils the need of small businesses and home users

Limited functionality supported e.g. no support for data recovery, complicated transactions etc.

Popular programs used for this are usually part of Operating System of computer.

Decentralization of data

Not meant for high volume of data

Redundancy and Integrity issues of data

Integrated Database Environment In an integrated Database Management System environment, the database provides an interface b/w the application programs & data. When changes are made to the data representation, the metadata maintained by the DBMS is changed but the DBMS continues to provide data to application programs in previously used way. This is called data independence. This made program to continue irrespective of changes made in data. In DBMS, all data files are integrated into one system which helps in reducing data redundancies & making data management more efficient. Also, DBMS provides centralized control of the operational data.

Integrated database environment provides the following advantages and disadvantages: Advantages

Disadvantages

Flexible

Difficult to learn

Good for large volume of data

Database software are not packaged with operating system and needs to be purchased separately

Fulfils the need of medium to large sized organizations

Requires skilled administrators to administer data

Centralized storage for all relevant data

Expensive

Ensures data integrity

Supports concurrent data access

Provides backup and recovery control

Advanced security

Fast retrieval of data

Example: Read more about Computer Network Assignment Help To understand the database environment, we can consider the operations of a bank which stores the information of its customers and accounts being maintained by the customers. One way to store the required information in files on computers.

In order to allow users to manipulate the information stored in files on computer, number of applications programs will be required to manipulate the files, e.g.

   

A program to debit or credit an account A program to add a new account A program to find the balance of an account A program to generate monthly statements

System programmers will create these application programs to meet the needs of the bank. New application programs will be required to add any new functionality. For example, suppose that the bank decides to offer a different kind of account, to achieve this, the bank will create new file that will contain information about all the accounts maintained in the bank, and it may have to write new application programs. Thus, with the time, the system will acquire more files and more application programs to support the required functionalities.

To overcome this problematic situation which occurred due to file processing system, we can use the integrated database environment, where all customer data from the bank will be stored in centralized database server and can be retrieved from the program written once. Also it will be easy to add or remove any functionality as per requirement. E.g. if bank want to propose new type of saving account, there is no need to create a new program to achieve this. This can be added by just creating new bank account type in metadata which is stored in centralized database and also it will be accessible from the same program, hence no modification is required in the application program as well.

Task 2 Task 2.1 Schema for the Proposed Database Below table shows Schema with all Entity Classes and Attributes for Online Movie Sales along with Subclasses and other details Entity Class

Attribute

Constraints or other Description

Customer

customerId

Primary Key, Not null

firstName

Not null

lastName

Not null

contactNo

Not null

password

Not null at least 6 characters

email

Not null

Multivalued composite with shippingAddresses

components name, street, city, state, zipcode

CreditCard

accountNo

Primary Key, Not null Foreign Key, Not null

Movie

DVD

customerId

(Customer)

expiration

Not null

type

Not null

movieId

Primary Key, Not null

Title

Not null

gener

Not null

media

like “DVD� determines subclass

languages

Subclass of Movie

videoFormat

Not null

captioning

Not null

quantity

Not null

cost

Not null

Sale

saleId

Primary Key, Not null Foreign Key, Not null

customerId

(Customer) Foreign Key, Not null

ShoppingCart

movieId

(Movie)

accountNo

Foreign Key, Not null (CreditCard)

totalCost

Not null

dateSold

Not null

cartId

Primary Key, Not null Foreign Key, Not null

customerId

(Customer)

dateCreated

Not null

Relationship Types and Relation details for Online Movie Sales in below table Relationship Type

Entity Class

Entity Class

Cardinality Ratio

Purchases

Customer

Sale

one-to-many

Includes

Sale

Movie

many-to-many

Selects

Customer

ShoppingCart

one-to-many

Includes

ShoppingCart

Movie

many-to-many

Includes

Customer

CreditCard

one-to-many

Attributes

quantity

quantity

This schema is normalized up to 3NF.



Schema does not repeating Elements or Groups of Elements, all tables have single tuple and each cell of tables have a single value of attribute hence it is following atomicity and fulfill all requirement of 1NF.



In Some table multiple making a primary key , No partial dependency and transitivity dependency so it follows 2NF and 3NF also

Customer (customerId, firstName, lastName, email, contactNo, password) CreditCard (accountNo, customerId, type, expiration) ShippingAddresses (customerId, addressNo, street, city, state, zipCode) ShoppingCart (cartId, customerId, dateCreated) CartDetail (cartId, movieId, quantity) MovieDVD (movieId, title, genre, videoFormat, language, captioning, quantity, cost) Sale (saleId, customerId, movieId, quantity, totalCost, dateSold, accountNo) All tables are following below 1NF: contains, no multi-valued Attribute 2NF: no partial dependency 3NF: no transitive dependency Read more about Computer Programming Assignment Help

Task 2.2 Entity Relation Diagrams Entity–relationship model for online DVD Sales contain 6 Entities and five relations including one sub class, it also include attribute and composite attribute.

Below is the Entity Relation Diagram

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