Domains, Database Management System

Assignment Help:

A domain is a set of permissible values that can be given to an attribute. So each attribute in a table has a definite domain. Values to these attributes cannot be assigned outside their domains.

In the example given above if domain of PERSON_ID is a set of integer values from 1 to

1000 than a value outside this range will not be valid. Many other common domains may be age between 1 and 150. The domain can be definite by assigning a type or a format or a range to an attribute. For instance, a domain for a number 501 to 999 can be particular by having a 3-digit number format having a range of values between 501 and 999. Therefore, please note the domains can also be non-contiguous. For instance, the enrolment number of IGNOU has the last digit as the check digit, therefore the nine- digit enrolment numbers are non continuous.


Related Discussions:- Domains

What is the use of union and intersection operation, What is the use of Uni...

What is the use of Union and intersection operation? Union: The result of this operation contains all tuples that are either in r1 or in r2 or in both r1 and r2.Duplicate tuple

What is recovery management component, What is recovery management componen...

What is recovery management component? Ensuring durability is the responsibility of a software component of the base system known as the recovery management component.

Er database theoretical and modeling database system, Need an expert in ER ...

Need an expert in ER database theoretical and modeling database system Project Description: Need an expert in ER database theoretical and modeling database systems? Skills

Search the salary of employees who are not ‘analyst’ , Example- Search the ...

Example- Search the salary of employees who are not 'ANALYST' but get a salary below than or equal to any people employed as 'ANALYST'. SELECT EMPNO, ENAME, JOB, SAL FROMEMP

What is the need for triggers, What is the need for triggers? Triggers ...

What is the need for triggers? Triggers are useful mechanisms for alerting humans or for starting particular tasks automatically when particular conditions are met.

Example of weak entity, Consider the entity type dependent related to emplo...

Consider the entity type dependent related to employee entity, which is used to keep track of the dependents of every employee. The attributes of dependents are: name, sex, birth d

Define null values, Define null values. In some cases a certain entity ...

Define null values. In some cases a certain entity may not have an applicable value for an attribute or if we do not know the value of an attribute for a certain entity. In the

What do you mean by atomicity and aggregation, What do you mean by atomicit...

What do you mean by atomicity and aggregation? Atomicity : Either all actions are carried out or none are. Users should not have to worry about the effect of incomplete trans

Oracle/sql, can you create a database for me in oracle/sql

can you create a database for me in oracle/sql

Provide examples of different types of time and date formats, Provide Examp...

Provide Examples of different types of Time and Date formats.  It's most common store dates using a dash (-) as a colon (:)and the delimiter as the time delimiter. The given fo

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd