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 the exists and unique functions of sql, Explain the EXISTS and UNIQ...

Explain the EXISTS and UNIQUE functions of SQL. Give an example for each? EXISTS: The EXISTS function takes one parameter that is a SQL statement. If any records exist which

Database administrator, The Database administrator (DBA) uses the data dict...

The Database administrator (DBA) uses the data dictionary in each phase of a database life cycle, beginning from the data gathering phase to the design, execution and maintenance p

Give expression in both tuple calculus and domain calculus, Consider the fo...

Consider the following relational schema: Doctor(DName,Reg_no) Patient(Pname, Disease) Assigned_To (Pname,Dname) Give expression in both Tuple calculus and Domain calculus for

E-commerce and business intelligence systems., Your friend owns and operate...

Your friend owns and operates a wholesale shoe business with annual revenues of $5 million dollars. His wholesale business specializes in supplying and supporting retailers with sh

DBMS, what is specialization?

what is specialization?

What is a cascading update, What is a cascading update? Referential int...

What is a cascading update? Referential integrity constraints needs that foreign key values in one table correspond to primary key values in another. If the value of the primar

File Management Principles, What are the requirements to ensure the objecti...

What are the requirements to ensure the objectives of file management principle is realized?

What is a select operation, What is a SELECT operation? The select oper...

What is a SELECT operation? The select operation selects tuples that please a given predicate. We use the lowercase letter σ to denote selection.

Linear commit protocol, With the linear commit protocol, sites are connecte...

With the linear commit protocol, sites are connected in a chain, and the subtransaction at the left-hand end of the chain initiates the protocol. Propose a crash recovery protocol

Give the general form of sql query, Give the general form of SQL query? ...

Give the general form of SQL query? Select  A1, A2............., An From  R1, R2..............., Rm Where  P

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