Introduction to Data Objects, Attributes and Relationships
When data modelling is used as a requirement analysis technique the analysis begins by creating models for objects. A data objects can be defined as:
It is a representation of information that must be understand by the software.
It is defined almost in the same manner as the objects of the OOA. Data objects can be external entities things occurrences or events roles organizational units, places or structures. It can be better understood with the help of an example:
A person busies a scoter.
Here person and scooter are the data objects. So the attributes of each one and a relationships between both are defined. In this way they are linked with each other. This example is shown in fig 7.30
As we can see in fig 7.25, that each objects has some attributes and they are connected with each other via a link. These relationships are always defined by the context of the problem that is beings analyzed.
A data objects encapsulate the data so there is so reference within objects to operations that act on the data. That why are objects can be represented as a table 7.3.
In table 7.3, various attributes of data objects scooter are defined.
In the table the attributes of data scooter are specifically named and their respective entries are also made. Id number is an identifier model and id number represent the naming attributes. Body type and color are descriptive attributes and the own of the scooter is the referential attributes ties one data objects to another.
So, this attributes makes the link between scooter and the person who buss it. The body of the table 7.3 represents specific instances of the data objects. For example model LA400, id number B23 of body type sports with color blue and which is bought by B, represents an instance of the data object scooter.
There are some major characteristics to define objects attributes. They are described below:
Additionally one or more of the attributes must be defined as an identifier where the identifier attributes becomes a key attributes when we want to find an instance of the data objects. The values of the identifier must be unique. Attributes for data objects are determined inexactly the same way as suggested for attributes defined as part of objects oriented analysis.
To reduce the redundancy and to provide consistency in table these data objects tables are formalized by applying a set of normalization rules that will result in a relational model for the data. These normalization rules are given below:
1. A given instance of a data objects has one and only one value for each objects.
2. Attributes represent elementary data items they should contain no internal structure.
3. When more than one attributes is used to identify a data objects be sure that descriptive and referential attributes represent a characteristics of the entire objects and not a characteristic of some things that would be identified by only part of the identifier.
All non identifier attributes must represent some characteristic of the instance named by the identifier of the data objects and describe some other attributes that is not an identifier.
Latest technology based Software Engineering Online Tutoring Assistance
Tutors, at the www.tutorsglobe.com, take pledge to provide full satisfaction and assurance in Data Objects Attributes and Relationships homework help via online tutoring. Students are getting 100% satisfaction by online tutors across the globe. Here you can get homework help for Data Objects Attributes and Relationships, project ideas and tutorials. We provide email based Data Objects Attributes and Relationships homework help. You can join us to ask queries 24x7 with live, experienced and qualified online tutors specialized in Data Objects Attributes and Relationships. Through Online Tutoring, you would be able to complete your homework or assignments at your home. Tutors at the TutorsGlobe are committed to provide the best quality online tutoring assistance for Software Engineering homework help and assignment help services. They use their experience, as they have solved thousands of the software engineering assignments, which may help you to solve your complex issues of Data Objects Attributes and Relationships. TutorsGlobe assure for the best quality compliance to your homework. Compromise with quality is not in our dictionary. If we feel that we are not able to provide the homework help as per the deadline or given instruction by the student, we refund the money of the student without any delay.
tutorsglobe.com electric kettle assignment help-homework help by online water heaters tutors
Theory and lecture notes of Introduction and Bio-amplifier requirements all along with the key concepts of Ideal Amplifier, Non-Ideal Amplifier, Negative Feedback and Operational Amplifier. Tutorsglobe offers homework help, assignment help and tutor’s assistance on Introduction and Bio-amplifier requirements.
Morphological and Genetic adaptations of Microorganism tutorial all along with the key concepts of Microbial adaptation to Marine and Freshwater Environments, Marine and freshwater environments, Polymerase Chain Reaction and temperature-stable DNA polymerase
Theory and lecture notes of Change in Price all along with the key concepts of change in price, Slutzky Equation, Slutzky Decomposition, Labor Supply application. Tutorsglobe offers homework help, assignment help and tutor’s assistance on change in price.
Theory and lecture notes of Two Proportions all along with the key concepts of Two proportions, homework help, assignment help and two parameter testing tutors. Tutorsglobe offers homework help, assignment help and tutor’s assistance on Two Proportions.
theory and lecture notes of construction and mechanism of operation all along with the key concepts of construction of bjt, operation of n-p-n bjt, current components, minority carrier profile and notation to an n-p-n bjt. tutorsglobe offers homework help, assignment help and tutor’s assistance on construction and mechanism of operation.
tutorsglobe.com bio gas assignment help-homework help by online energy crisis tutors
Not so long ago, the image of the non-executive director was that of an avuncular figure offering kindly guidance and advice to the board concerning the direction of the company.
tutorsglobe.com factors governing ionization energy assignment help-homework help by online ionisation potential tutors
Get tailored solutions from Electrostatics Assignment Help service at pocket-friendly prices and score maximum grades with PhD tutors.
tutorsglobe.com software complexities assignment help-homework help by online software engineering tutors
Avail the premium Community and Social Reconstruction Assignment Help at affordable prices with apt tutors to secure top grades.
tutorsglobe.com mechanism of hearing assignment help-homework help by online ear tutors
Get high-quality Network Architecture Assignment Help with 24x7 apt tutors at reasonable prices to secure notable grades!!
www.tutorsglobe.com offers creation of control flow diagram homework help, assignment help, case study, writing homework help, online tutoring assistance by computer science tutors.
1957395
Questions Asked
3689
Tutors
1473801
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!