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.

 

Posted Date: 7/26/2013 6:13:24 AM | Location : United States

Ask an Expert

Related Discussions:- Explain about foreign key, Assignment Help, Ask Question on Explain about foreign key, Get Answer, Expert's Help, Explain about foreign key Discussions

Write discussion on Explain about foreign key
Your posts are moderated

Write your message here..

Related Questions

Key constraint - relational constraints, This constraint shows that the key... This constraint shows that the key attribute value in each tuple must be unique, i.e., no two tuples have the similar value for the key attribute. This is because the value of the

Find names of employees, Consider the relations EMP(ENO,ENAME,AGE,BASIC_S... Consider the relations EMP(ENO,ENAME,AGE,BASIC_SALARY) WORK_IN(ENO,DNO) DEPT(DNO,DNAME,CITY) Express the following queries in SQL (i) Find names of employees who work in a dep

Explain the form of the create view command, We define a view in SQL throug... We define a view in SQL through using the create view command. To describe a view, we must provide the view a name and must state the query in which computers the view. The form of

Data storage and retrieval services, An Enterprising group of Entrepreneurs... An Enterprising group of Entrepreneurs introduced a new business named StoreItRite which is based on data storage and retrieval services. It provides the services and the company c

Explain weak and strong entity sets, Explain weak and strong entity sets? ... Explain weak and strong entity sets? Weak and Strong entity sets: A physically powerful entity set has a primary key. All tuples in the group are distinguishable through that k

What is known as sequential file organization, What is known as sequential ... What is known as sequential file organization? In the sequential file organization, the records are kept in sequential order, according to the value of a "search key" of every

List the drawbacks of relational database system, List the drawbacks of rel... List the drawbacks of relational database system A) Repetition of data B) Inability to s certain information.

Query optimization in database system, Problem : AirwaysCentre, an inte... Problem : AirwaysCentre, an international airline booking company currently uses a relational database system for their operations, which includes the following relations: P

Sql, Events4Fun is an event management company in Europe with branches in S... Events4Fun is an event management company in Europe with branches in South America as well. The company is well-known for its efficiency, good-quality services, and affordable char

Lock, intent locking intent locking