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

Create records in a table - data structures, In this exercise you will crea...

In this exercise you will create ten records, each containing the following fields: student name, class:  Freshman, Sophomore, Junior or Senior, Major:  Liberal Arts or General Sci

Authorisation, Authorisation Authorisation is the culmination of the ad...

Authorisation Authorisation is the culmination of the administrative policies of the organisation.  As the name shows, authorisation is a set of rules that can be used to verif

Define the term- actors and data stores, Define the term- Actors and Data...

Define the term- Actors and Data Stores Actors: An actor is the active object which drives data flow graph by producing or consuming values. Actors are attached to inputs a

Weak entity, An example of a weak entity is Staff because the availabilityI...

An example of a weak entity is Staff because the availabilityID cannot be uniquely identified unless it is used in conjunction with the foreign key known as availabilityID in the A

Help, #questiononsider the following relation: CAR_SALE =(CAR_ID,oPTION_TYP...

#questiononsider the following relation: CAR_SALE =(CAR_ID,oPTION_TYPE, Option_listpreice, Sale_date, Option_discountedprice)..

List the reg-no of vehicles owned in relational algebra, Given the followin...

Given the following relations Vehicle (Reg_no, make, colour) Person(eno, name, address) Owner(eno, reg_no) Write expressions in the relational algebra to answer the following

What is omr, What is OMR? OMR (Optical Mark Recognition) is the transla...

What is OMR? OMR (Optical Mark Recognition) is the translation of marks - or the absence of marks - but not the shape of the mark on forms that have small circles ("also called

Oracle fusion middleware, Oracle Fusion Middleware: Key Skills: Consul...

Oracle Fusion Middleware: Key Skills: Consulting,Architect, Oracle Fusion Middleware,ECM, UCM, Stellent,Identity Management, SOA Suites, BPEL, ESB,OAM,OIM,J2ee, Java, Livelink

What is the main advantage of the object model, What is the main advantage ...

What is the main advantage of the object model? What are its different components? The object model focuses on the logical data structures. Each object model comprises of many

Explain the timestamp ordering protocol, Timestamp Ordering Protocol A ...

Timestamp Ordering Protocol A timestamp is a tag that can be attached to any transaction or any data item, which indicates a specific time on which the transaction or data item

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