Relationship cardinality, Database Management System

Assignment Help:

Cardinality shows the number of instances of an entity associated with another entity participating in a relationship. Depend on the cardinality binary relationship can be further dividing into the following categories:

  • One-to-one: An entity in A is related with at most one entity in B, and an entity in B is associated with at most one entity in A.

 

Example: Relationship between university/college and principal

1656_Relationship Cardinality.png

One college only have at the most one principal and one principal can be assigned to only one college.

Likewise we can define the relationship among Vice Chancellor and university.


Related Discussions:- Relationship cardinality

Candidate keys, Super keys of a relation can have extra attributes. Candida...

Super keys of a relation can have extra attributes. Candidate keys are minimal super key, i.e. such a key have no extraneous attribute. An attribute is known as extraneous if even

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

Data replication, Data Replication "If a relation R has its copies kept...

Data Replication "If a relation R has its copies kept at two or more sites, then it is considered replicated". But why do we replicate a relation? There are several advan

What is meant by buffer blocks and disk buffer, What is meant by buffer blo...

What is meant by buffer blocks and disk buffer   The blocks residing temporarily in main memory are referred to as buffer blocks. The area of memory where blocks reside t

What are the various properties of relational tables, What are the various ...

What are the various properties of Relational tables? Relational tables have 6 properties: 1. Each row is unique. 2. Column values are of the same kind. 3. Values are

What is magnetic disks, What is magnetic disks?explain it? Magnetic dis...

What is magnetic disks?explain it? Magnetic disk provides the bulk of secondary storage of modern computer system. The disk capacity is growing at over 50% per year. But the st

Advantages of data distribution, Advantages of Data Distribution The pr...

Advantages of Data Distribution The primary benefit of distributed database systems is the ability to access and share data in a reliable and efficient manner.

Create student database and retrieve course taught by king, Create student ...

Create student database and retrieve course name taught by king? STUDENT (name, student#, class, major) COURSE (course name, course#, credit hours, department) SECTION (secti

Explain the timestamps for read operations, Timestamps For Read operations:...

Timestamps For Read operations: If TS (T) If TS (T) >= W-timestamp (Q), then the transaction T is trying to read a value of data item Q which has been written and committed

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