Introduction to Data Objects Attributes and Relationships
A Data model consists of three different types of interrelated information data objects attributes that describe an object, and differentiate one object from other and the relationships that connect data objects to one another.
Data Objects: By composite information we mean something that has a number of different properties or attributes which can differentiate it from other information. Data objects represent such composite information which must be familiar to or understood by the software. Thus a single value is not sufficient for a valid data object. But a group of such individual values (e.g. colour weight can collectively) form a valid data object.
A valid data object can be of any type a thing an external entity an occurrence a role an organizational unit a place or a structure. These data objects are related to one another. For example teacher and school are towing data objects. The relationship between them can be defined as the teacher teaches in the school.
A data object encapsulates only data. There is no reference to processes or operations that acts on data within a system.
Attributes: An attributes defines the properties of a data object. It also forms the basis on which two data objects can be distinguished from one another. So attributes can be used to:
Name an instance of a data object,
Describe an instance, and
Make reference to another instance of some other data objects (referencing).
One or more attributes can be collectively used as an identifier of a particular entity of a data object. Such collective attributes are known as keys. Referring to a data object student a reasonable identifier must be his school college ID number.
Relationships: Every data object defined in a system are interrelated to one another (may be not to all) in some ways. Relationships are generally bidirectional, which can be either shown as both sided arrows and no arrows on both sides. For example, consider tow data objects medicine and medicine store. Their relationship is shown in fig 4.2.
A set of object relationship pairs can be defined between these two objects:
A medicine store orders medicine.
A medicine store displays medicine.
A medicine store stocks medicine.
A medicine store sells medicine.
A medicine store returns medicine.
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.
theory and lecture notes of binomial theorem all along with the key concepts of binomial theorem, binomial expansion, combinations, pascal's triangle and binomials rose to a power. tutorsglobe offers homework help, assignment help and tutor’s assistance on binomial theorem.
Theory and lecture notes of Investment Spending all along with the key concepts of investment spending, homework help, assignment help, building blocks of the flexible-price model. Tutorsglobe offers homework help, assignment help and tutor’s assistance on Investment Spending.
Factors affecting Population tutorial all along with the key concepts of Birth rate or Natality rate, Death or Mortality rate, Age distribution, Permanence of movement, Migratory selection, Effects on populations, Abiotic and biotic factors
tutorsglobe.com factors affecting electron affinity assignment help-homework help by online electron affinity tutors
separation of peptides tutorial all along with the key concepts of protein purification, purification technique on the basis of solubility, purification technique on the basis of molecular size, kinds of gel materials
TutorsGlobe.com Chemistry Tutorial Assignment Help-Homework Help by Online Chemistry Tutors
Microscope and Specimen Preparation tutorial all along with the key concepts of The Microscope, Light Microscope, Bright Field Microscope, Dark-Field Microscope, Phase-Contrast Microscope, Fluorescent Microscope, Microscope Resolution and Electron Microscope
Theory and lecture notes of Construction and Mechanism of Operation all along with the key concepts of Physical Structure, Device Operation, Threshold Voltage and CMOS Structures. Tutorsglobe offers homework help, assignment help and tutor’s assistance on Construction and Mechanism of Operation.
Hire qualified Computational Science Assignment Help tutors and leave your worries aside and get A++ solutions at fair prices and score top grades.
Areas that are covered by a cost reduction programme - Product Design, Production Planning, Direct Materials Cost Reduction, Direct Labour Cost Reduction, Overheads Cost Reduction.
Excel in your grades by hiring qualified tutors of History of Africa Assignment Help at budget-friendly prices.
access chemistry tutorial all along with the key concepts of introduction to chemistry, branches of chemistry, importance of chemistry, how does chemistry affect our lives
tutorsglobe.com shape of s-orbitals assignment help-homework help by online shapes of orbitals tutors
Insect-Insect Relationships tutorial all along with the key concepts of History of Insect-Insect Relationships, Insect Predators, Insect Parasitoids, Insects as Predators and Parasitoids, Host/prey location and acceptance, Host/prey acceptance and manipulation
tutorsglobe.com geothermal energy assignment help-homework help by online energy crisis tutors
1952084
Questions Asked
3689
Tutors
1492749
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!