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

Explain tuple variable, Define tuple variable? Tuple variables are used...

Define tuple variable? Tuple variables are used for comparing two tuples in the same relation. The tuple variables are explained in the from clause by way of the as clause.

What are the acid properties?, Question 1 What are the advantages of DBMS ...

Question 1 What are the advantages of DBMS approach in managing data? Question 2 What are the services provided by a database system Question 3 List and briefly describe

Generalization and specialization, design a generalization specialization h...

design a generalization specialization hierarchy for a motor vehicle sales company. the company sells motorcycles, passenger cars, vens and buses.

How does query tree represent relational algebra expression, How does a que...

How does a query tree represent a relational algebra expression?  Discuss any three rules for query optimisation, giving example as to when should each rule be applied.     Ans

Draw an e_r model in oracle, Draw an E_R Model for the following: An or...

Draw an E_R Model for the following: An organization uses number of items of a equipment to generates goods. Each item is at one LOCATION, of one TYPE and has a DETAILED_DISCRI

Each statement should have a where clause, Submit SQL SELECT Statements to ...

Submit SQL SELECT Statements to demonstrate several reports off your database, according to the following guidelines: You must submit at least 5 SELECT Statements. Each

Explain the concept of modeling with objects, Explain the concept of Modeli...

Explain the concept of Modeling With Objects A model is a conceptual representation of a specification, design or system from a particular point of view. A modelling language

Explain domain calculus, Explain Domain calculus Domain calculus is one...

Explain Domain calculus Domain calculus is one of the types of the relational calculus. The formal specification of the domain calculus was planned after the development of the

Define the basic operations of the relational algebra, Define the basic ope...

Define the basic operations of the relational algebra?     Ans: Basic operators of relational algebra are: 1. Union (∪) - Selects tuples which are in either P or Q or in bot

Types of locks, Types of Locks There are two necessary types of locks: ...

Types of Locks There are two necessary types of locks: Binary lock : This locking mechanism has two states for to a data item: locked or unlocked Multiple-mode loc

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