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

aggregate functions-data manipulation language, Aggregate functions ...

Aggregate functions Some of these functions are min, count, max, and avg. These functions help in getting consolidated information from a set of tuples. Example:

Define about the stored procedure, Define about the Stored Procedure - ...

Define about the Stored Procedure - It's a set of T-SQL statements combined together to perform a single task formed by combining numerous small tasks. - When you essentiall

relationship with the owner entity, A database for the Service and Mainten...

A database for the Service and Maintenance (SM) section of a Computer sales and service Company has to be developed. SM gives after sales service to customers. SM branch has a numb

Data warehousing and business intelligence, I need help with data warehousi...

I need help with data warehousing and business intelligence course project about designing a data warehouse for a jewelry company that does not have one

Information system fundamentals, A full discription of the new, a discripti...

A full discription of the new, a discription of its components, and the bebefit it will provide a company. A disscussion of the information usedin the system. A disscussion of any

State the steps of object design, State the Steps of Object Design ...

State the Steps of Object Design Object design is a very iterative process in which various classes, relationships among objects are added when you move from one level to

E-commerce and business intelligence systems., Your friend owns and operate...

Your friend owns and operates a wholesale shoe business with annual revenues of $5 million dollars. His wholesale business specializes in supplying and supporting retailers with sh

Optimistic concurrency contents -write-set(t), write-set(T): Each data ite...

write-set(T): Each data items that are written by a transaction T

Column constraints-on delete cascade, CREATE TABLE prodtrans ( pno ...

CREATE TABLE prodtrans ( pno number (4) ptype char (1) CHECK (ptype in ('I','R','S')), qty number (5) FOREIGN KEY pno REFERENCES product (pno) ON DELETE CASCADE);

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