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

Explain hierarchical model, Explain Hierarchical Model ? Hierarchical ...

Explain Hierarchical Model ? Hierarchical Model - It was established to model several kinds of hierarchical organizations which exist in the real world. It uses tree structur

Which product produces the relation that has attributes, Which product prod...

Which product produces the relation that has attributes of R1 and R2 ? Cartesian product produce the relation which has attributes of R1 and R2

Design and building a distributed information system, The scenario You ...

The scenario You have been approached to design and implement a prototype of a distributed information system for a national car part retail outlet chain. The company comprises

What creates while a primary key is combined with a foreign, What it create...

What it creates while a primary key is combined with a foreign key? It creates Parent-Child relation ship between the tables that connect them while a primary key is combined w

Textbook ordering system, Question: Consider the following database rel...

Question: Consider the following database relations for a textbook ordering system used by a college bookshop: Book (b-copy#, bname, ISBN#, author, price, subject) Order (s#

Define deadlock prevention, Define deadlock prevention. Deadlock preven...

Define deadlock prevention. Deadlock prevention is a set of methods for ensuring that at least one of the four essential conditions like mutual exclusion, hold and wait, no pre

Managing databases, Code an Oracle Database trigger to enforce the constrai...

Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department.

Explain current page table and shadow page table, Explain current page tabl...

Explain current page table and shadow page table. The key idea behind the shadow paging method is to maintain two page tables during the life of the transaction: the current pa

Naïve bayesian approach-id3 algorithm, You are working for the ABC Telecom ...

You are working for the ABC Telecom and are given some customer records for data mining. You are asked to discover, from the data, patterns that characterize low-, medium- and high

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