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

Distinguish among a datareader class and a dataset class, Question (a) ...

Question (a) Concurrent access to data from a database is a normal part of application program usage. Describe three approaches to concurrency control (b) Distinguish among

horizontal fragmentation, Horizontal Fragmentation- Horizontal fragmentati...

Horizontal Fragmentation- Horizontal fragmentation groups together the tuples in a relation that are collectively used by the main transactions. A horizontal fragment is produced b

Illustrate the fifth normal form, Fifth Normal Form (5NF) These relatio...

Fifth Normal Form (5NF) These relations still have a difficulty. While defining the 4NF we mentioned that all the attributes depend upon each other. Whereas creating the two ta

What are the aggregate objects in the data dictionary, What are the aggrega...

What are the aggregate objects in the data dictionary? Views Match codes Lock objects.

Many-to-many relationship, For each m:n relationship type R, we make a new ...

For each m:n relationship type R, we make a new table (say S) to represent R. We also contain the primary key attributes of both the participating entity types as a foreign key att

What do you mean through integrity constraints, What do you mean through in...

What do you mean through integrity constraints? Integrity Constraints -An integrity constraint is a condition specified on a database schema and restricts the data in which

Explain the term- event, Event Occurrence of a process is called event...

Event Occurrence of a process is called event. In other words, the object can receive many input instructions. The changes which occur due to these instructions are known as e

Create an index for the table client, Create an index for the table Client,...

Create an index for the table Client, field CLIENT_NO of Q ? Command:   CREATE INDEX client_client_no ON client(client_no);

Microsoft access database assigment, Hello.I have database access assignmen...

Hello.I have database access assignment which consist of creation Form, Subform, Calculation, Macros

Explain the term - control as concurrent tasks, Explain the term - Control ...

Explain the term - Control as Concurrent Tasks As we know, any object can be implemented as a task in programming language or operating system. This is the most general approa

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