Define null value, Database Management System

Assignment Help:

Define NULL value

NULL value NULL means something is unknown. It does NOT mean null (the digit 0). Null is as well employed as attribute value for a particular entity in which attribute is not applicable for example name of child for unmarried.


Related Discussions:- Define null value

What is view in sql, What is view in SQL? How is it defined? Any relati...

What is view in SQL? How is it defined? Any relation that is not part of the logical model, but is made visible to a user as a virtual relation is known as a view. We descri

Define a relation schema, A Relation Schema represented by R(A1, A2, .....

A Relation Schema represented by R(A1, A2, ..., An) is made up of the relation name the list of attributes and R Ai that it contains. A relation is described as a set of tuples

State in detail about data flow diagram, What is a Data Flow Diagram?  ...

What is a Data Flow Diagram?  Data Flow Diagram: A data flow diagram is the graph that shows flow of data values from their sources in objects in the course of processes whic

What is data model explain object and data base models, What is data model?...

What is data model? Explain object based and record based data models? Ans: A data model is an abstract model in which describes how data is represented and accessed. (i)

Explain the internal architecture of 8086, Problem 1. Write an assembly...

Problem 1. Write an assembly program to find the smallest among two numbers Writing an assembly program to find the smallest among two numbers 2. Explain the intern

Design and building a distributed information system, prototype of a distri...

prototype of a distributed information system for a national car part retail outlet chain.

Describe drop table command or cascade of sql, Describe DROP TABLE command ...

Describe DROP TABLE command of SQL along with both the options - CASCADE and RESTRICT. DROP TABLE command - This command drops the specified table. Dropping a table also dro

SQL, Ask Write the SQL code that will create the table structure for a tabl...

Ask Write the SQL code that will create the table structure for a table named EMP _1. This table is a subset of the EMPLOYEE table. The basic EMP_1 table structure is summarized in

What are the categories of sql command, What are the categories of SQL comm...

What are the categories of SQL command? SQL commands are separated in to the following categories: 1. Data - Definitition Language 2. Data Manipulation language 3. Dat

Compare the nested-loop join and block-nested loop join, Compare the Nested...

Compare the Nested-loop join and block-nested loop join Ans: Nested  loop join - It is costly as worst case cost, no. of block accesses needed is n r * b s + b r   where b

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