What is foreign key, Database Management System

Assignment Help:

What is foreign key?

A relation schema r1 derived from an ER schema may contain among its attributes the primary key of another relation schema r2.this attribute is known as a foreign key from r1 referencing r2.  

 


Related Discussions:- What is foreign key

What is a database, What is a Database? To know what database is, we ha...

What is a Database? To know what database is, we have to start from data, which is the basic building block of any DBMS. Data: Facts, figures, statistics etc. having no pa

Entity integrity, Before defines the second type of integrity constraint, v...

Before defines the second type of integrity constraint, viz., Entity Integrity, we should be well-known with the concept of NULL. Mostly, NULL is intended as a basis for dealing

How many types of users works on database, How many types of users works on...

How many types of users works on database? Users are differentiated through the way they expect to interact along with the system (i) Application programmers-interact with

Define control files, Control Files : The redo and control files logs supp...

Control Files : The redo and control files logs support the rest of the architecture. Every database must have at least one control file, although you have more than one to guard

Business process model, Consider a research paper submission process. The p...

Consider a research paper submission process. The process starts when an author submits a draft research paper (the paper may have up to 3 authors) to the chair of the organizing c

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

Express the ways provided by mysql for pattern matching, Express the ways p...

Express the ways provided by MySQL for Pattern Matching? MySQL provides two kinds of pattern matching. 1) One is based on SQL patterns 2) Regular expressions.

Ordering of tuples, In a relation, tuples are not inserted in any definite ...

In a relation, tuples are not inserted in any definite order. Ordering of tuples is not defined as a part of a relation definition. Though, records may be structured later accordin

Increased parallelism-data replication, Increased parallelism : Since the r...

Increased parallelism : Since the replicated date has several copies a query can be distributed or can be answered from the smallest loaded site. Also, with more replicas you have

State about the advance object design, ADVANCE OBJECT DESIGN Introduct...

ADVANCE OBJECT DESIGN Introduction Analysis is the initial step of the OMT methodology. It is apprehensive with devising a precise, concise, correct and understandable mo

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