The first normal form (1nf), Database Management System

The First Normal Form (1NF)

Let us first describe 1NF:

Definition: A relation (table) is in 1NF if

1.      There are no duplicate tuples or rows in the relation.

2.      Every data value stored in the relation is one-valued

3.      Entries in a column (attribute) are of the similar kind (type).

Please note that in a 1NF relation the order of the attributes (columns) and tuples (rows) does not matter.

The first necessity above means that the relation must have a key. The key may be one attribute or composite key. It may even, possibly, have all the columns. The first normal form describes only the basic structure of the relation and does not determine the anomalies.

 

Posted Date: 3/7/2013 1:55:03 AM | Location : United States







Related Discussions:- The first normal form (1nf), Assignment Help, Ask Question on The first normal form (1nf), Get Answer, Expert's Help, The first normal form (1nf) Discussions

Write discussion on The first normal form (1nf)
Your posts are moderated
Related Questions
What is the role of ORDER By Clause? ORDER BY clause: The ORDER BY clause permits you to sort the records in your result set. The ORDER BY clause can just be used in select s

WHAT IS DSS? WRITE ITS REQUIREMENTS.

Related fields in a database are grouped in which form? Related data fields in a database are grouped to form a data record. (A record is a collection of related fields)

Task Partitioning, Sequencing and Project Planning The tasks required for the service might be broadly partitioned into: 0.      Set up database tables and account file


Draw entity relationship diagram for the following scenario. A university has many departments whereas each department belongs to that particular uni. That uni has also many bui

Explain four causes for failures in data warehouse projects


Develop a database broker framework to implement a persistence mechanism for the domain objects involved in the use case dealt with in Question 2.  a. Specify the attribute type

a)  Suppose we updated the catalog tables in real time, that is, after every update, insert, or delete SQL statement were executed-rather than only running RUNSTATS once every few