Domain constraints, Database Management System

Domain Constraints

Domain constraints are primarily formed for defining the logically correct values for an attribute of a relation. The relation allows attributes of a relation to be confined to a range of values, for instance, values of an attribute age can be restricted as Zero to 150 or a definite type like integers, etc.

                                                      REDUNDANCY AND ASSOCIATED PROBLEMS

Let us take the subsequent relation STUDENT

Enrolment no

Sname

Address

Cno

Cname

Instructor

Office

050112345

Rahul

D-27, main Road

Ranchi

MCS-011

Problem

Solution

Nayan

Kumar

102

050112345

Rahul

D-27, Main Road

Ranchi

MCS-012

Computer

Organisation

Anurag

Sharma

105

050112345

Rahul

D-27, Main Road

Ranchi

MCS-014

SSAD

Preeti

Anand

103

050111341

Aparna

B-III, Gurgaon

MCS-014

SSAD

Preeti

Anand

103

                                                                           Figure: A state of STUDENT relation

The above relation satisfies the properties of a relation and is said to be in first normal form (or 1NF). Theoretically it is convenient to have all the information in one relation as it is then likely to be simpler to query the database. But the relation over has the following undesirable kinds:

Posted Date: 3/7/2013 1:41:24 AM | Location : United States







Related Discussions:- Domain constraints, Assignment Help, Ask Question on Domain constraints, Get Answer, Expert's Help, Domain constraints Discussions

Write discussion on Domain constraints
Your posts are moderated
Related Questions
Design a gennalization and specialization hierarchy for an automobile sales company

List any eight applications of DBMS. a) Universities b) Airlines c) Banking d) Credit card transactions e) Tele communication f) Sales g)Finance h) Manufac


The cross-section of twisted pair The cross-section of each and every strand of the twisted pair is π/4 square mm. A 10-km length of this type of material, with two strands per

Question: (a) Use the following business rules to produce the E-R diagram. You should clearly show all the minimum and maximum cardinality constraint on each side of the relati

A database to track your progress in your college program will track your progress towards graduation! A database that has information containing the classes that you have taken, c

I want a script that will run, and update my virtual machine's LAN settings (proxy server and port), and also re-configure the Firefox User Agent. I want a script that will run,

Do you have experts of the dbms

Explain the two types of participation constraint. 1. Total: The participation of an entity set E in a relationship set R is said to be total if each entity in E participates i

Give the reasons for allowing concurrency? The reasons for allowing concurrency is if the transactions run serially, a short transaction might have to wait for a preceding long