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 disadvantages of a file processing system, Explain the disadvan...

Explain the disadvantages of a file processing system? Ans: Disadvantages of File Processing Systems include: 1) Data Redundancy 2) Data Inconsistency 3) Difficult to acce

What is the use of keyword isa, What is the use of keyword ISA? The use...

What is the use of keyword ISA? The use of keyword ISA is to show that a class is a specialization of another class.

Write the sql queries using data manipulation language, Problem 1. Writ...

Problem 1. Write the SQL queries using Data Manipulation Language (DML) statements. Insert values into student table with field names using insert command Display the

Design a query plan for distributed query, (a) Design a query plan for the ...

(a) Design a query plan for the following distributed query: An application at site B wants to compute a join of STUDENT ? Id=StudId TRANSCRIPT where STUDENT (Id,Major) is at site

What is an object design, What is an object design? Object design is a ...

What is an object design? Object design is a very interactive method, which decides the relationship among objects, classifies operations on classes, determines overall system

Managing database, 10A.53 Code an Oracle Database trigger to enforce the ...

10A.53 Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department. 10A.54 Code an Oracle Database trigger to allow the

Data files indices and data dictionary, The indices are accumulated in the ...

The indices are accumulated in the index files. The data is accumulated in the data files. Indices give fast access to data items. For example, a book database may be managed in th

Which operation is used if we are interested certain columns, Which operati...

Which operation is used if we are interested in only certain columns of a table? PROJECTION operation is used if we are interested in only certain columns of a table.

What is a data dictionary, What is a data dictionary?  A data dictionar...

What is a data dictionary?  A data dictionary is a data structure which keeps Meta data about the structure of the database i.e.  the schema of the database.

Explain the data access protocol, (a) Explain the three types of potentia...

(a) Explain the three types of potential mistake which could occur if concurrency control is not properly enforced in the database system. Support your answer with appropriate ex

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