Referential integrity constraint - relational constraints, Database Management System

Assignment Help:

It defines that the tuple in one relation that refers to another relation must refer to an existing tuple in that relation. This constraint is states on two relations (not essentially distinct). It uses a concept of foreign key and has been dealt with in more factors in the next unit.

Example

 

1599_referential integrity constraint.png

In the example given above, the value of C^ in every R tuple is matching with the value of C# in some S tuple. If a tuple has values (A6, B2, and C4) is added then it is invalid as referenced relation S doesn't contain C4. Therefore, it will be a violation of referential integrity constraint.


Related Discussions:- Referential integrity constraint - relational constraints

What is meant by mean time to failure, What is meant by mean time to failur...

What is meant by mean time to failure? The mean time to failure is the amount of time that the system could run continuously without failure.

EER models, Ask question #MinimThe Georgia Tech Library (GTL) has approxima...

Ask question #MinimThe Georgia Tech Library (GTL) has approximately 16,000 members, 100,000 titles, and 250,000 volumes (an average of 2.5 copies per book). About 10 percent of the

Explain the disadvantages of a file processing system, Explain the disadvan...

Explain the disadvantages of a file processing system? Ans: Disadvantages of File Processing Systems include: 1) Data Redundancy 2) Data Inconsistency 3) Difficult to acce

Please answer me., gyan gurukul is a software company that provides softwar...

gyan gurukul is a software company that provides software related solution.

Design a large scale system, Question: (a) Why is it important to know...

Question: (a) Why is it important to know the architecture rather than to start requirement capture when designing a large scale system? (b) Who are the different people in

Explain the data access protocol, (a) Explain the three types of potentia...

(a) Explain the three types of potential mistake which could occur if concurrency control is not properly enforced in the database system. Support your answer with appropriate ex

Shared lock or read lock, Shared lock or Read Lock It is requested ...

Shared lock or Read Lock It is requested by a transaction that needs to just read the value of data item. A shared lock on a data item does not permit an exclusive lock

Write short note on data models, Write short note on Data models? Data...

Write short note on Data models? Data models: A data model is an abstract model which elaborates how data is represented and accessed. The term data model has two commonly ac

Find out the names of all employees from database, Find out the names of al...

Find out the names of all employees who work for first Bank Corporation from database. SELECT EMPLOYEE_NAME FROM WORKS WHERE COMPANYNAME = ‘First Bank Corporation';

Explain forms based and graphical interface, Explain forms based and graphi...

Explain forms based and graphical interface? Forms based and graphical interface: graphical user interface (GUI) is a kind of user interface which permits people to interact

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