Explain about foreign key, Database Management System

Assignment Help:

What is Foreign Key

Foreign Key: Sometimes we may have to work with an attribute that does not have a primary key of its own. To recognize its rows, we have to use the primary attribute of a related table. Such a copy of another related table's primary key is known as foreign key.

 


Related Discussions:- Explain about foreign key

Cube building in dataware housing , 1) Define a job scheduling strategy tha...

1) Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pict

Transaction, what are the states of transaction?

what are the states of transaction?

Queries, Write a query that display ename annual salary and comm from emp t...

Write a query that display ename annual salary and comm from emp table

Convert erd to rdm model, Regional Gardens has many nurseries, including Wa...

Regional Gardens has many nurseries, including Wagga Wagga, Bathurst, Albury, Orange, and Dubbo. Each nursery is known by its campus code, eg WW, B, A, O and D respectively. Additi

What is substitutability, What is substitutability? Any method of a cla...

What is substitutability? Any method of a class-say A can equally well be adjured with any object belonging to any subclasses B of A. This characteristic leads to code reuse, a

ER Diagram, Soccer player ER Diagram to Relational database schema

Soccer player ER Diagram to Relational database schema

Normalization, Consider a bank that has a collection of sites, each running...

Consider a bank that has a collection of sites, each running a database system. Suppose the only way the databases interact is by electronic transfer of money between one another,

Explain retrieval in qbe, Explain retrieval in QBE? Retrieval in QBE : ...

Explain retrieval in QBE? Retrieval in QBE : A "GUI" for expressing queries. Based on the Domain Relational Calculus (DRC) Actually invented before GUIs. Very co

What is a database graph, What is a database graph? The partial orderin...

What is a database graph? The partial ordering implies that the set D may now be viewed as a directed acyclic graph, known as a database graph.

Describe the relational model, a) Distinguish between ‘database' and ‘Data...

a) Distinguish between ‘database' and ‘Database Management Systems (DBMS)'. b) List and briefly describe five potential benefits of the database approach compared to conventio

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