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

What is meant by object identifiers, What is meant by object identifiers? ...

What is meant by object identifiers? Object-oriented systems use an object identifier to recognize objects. Object identifiers are unique: that is every object has a single ide

What are partial and natural key, What are partial, alternate,, artificial,...

What are partial, alternate,, artificial, compound and natural key? Partial Key: It is a set of attributes that can uniquely recognize weak entities and that are related to s

Fds in relationships and teaches relationship, FDs in Relationships:  E...

FDs in Relationships:  Enrols Relationship: None as it is many to many Teaches Relationship : Course code → Instructor Instructor → Course code The next question is:

The external or view level in dbms, The External or View Level The ex...

The External or View Level The external or view level is the highest level of abstraction of database. It gives a window on the conceptual view, which permits the user to see

Example of sequences, Example : Create a sequence named SEQSS that starts a...

Example : Create a sequence named SEQSS that starts at 105, has a step of 1 and can take maximum value as 2000.  CREATE SEQUENCE SEQSS START WITH 105 INCREMENT BY 1 MAX VA

Which database object does not physically exist, Which database object does...

Which database object does not physically exist? A view database object does not physically exist.

What is a block and a block number, What is a block and a block number? ...

What is a block and a block number? A block is a contiguous sequence of sectors from a single track of one platter. Every request specifies the address on the disk to be refere

What are the key features of oracle, What are the key features of Oracle? ...

What are the key features of Oracle? Key features of Oracle are as follows: • Read Consistency • Concurrency • Locking Mechanisms • Quiesce Database • RAC • Portability

The advantages of a database management system, The advantages of a databas...

The advantages of a database management system (DBMS) include :- Data integrity and elimination of duplication.

What is bcnf boyce-codd normal form, BCNF Boyce-Codd Normal Form A rel...

BCNF Boyce-Codd Normal Form A relation schema R is in BCNF if it is in 3NF and accepts an additional constraint that for every FD X A, X has to be a candidate key. If a relati

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