What is null described testing for null in sql?, Database Management System

Assignment Help:

What is NULL? Give an example to described testing for NULL in SQL?

The NULL SQL keyword is used to represent either a missing value or a value which is not applicable in a relational table. Consider there is a relation:

Person(id, name, address, phone)
Now to search ids and names of person who do not have a phone is:
Select id, name
from Person
where phone is null


Related Discussions:- What is null described testing for null in sql?

Why we use delegation to share implementation, Use Delegation to Share Impl...

Use Delegation to Share Implementation The delegation " Delegation comprises of catching an operation on one object and sending it to other object which is part, or related to

Explain thomas write rule, Explain Thomas' Write rule.  Show how it is diff...

Explain Thomas' Write rule.  Show how it is different from timestamp ordering protol Ans: In timestamp-based concurrency control the thomas Write rule is a rule. Given a Timest

Define the five basic operators of relational algebra, Define the five basi...

Define the five basic operators of relational algebra? Five basic operators of relational algebra are: 1. Union (∪∪∪∪) - Selects tuples which are in either P or Q or in both

Short note on mid square method of hashing, Short Note on mid Square Method...

Short Note on mid Square Method of hashing? Mid square method of hashing: In the method midsquare hashing, the key is squared and the address selected from the center of the s

Insert statement reverses storage space and transfers value, A field-groups...

A field-groups statement or an insert statement reverses storage space and transfers values. False.

What are the uses of the information in the data dictionary, What are the u...

What are the uses of the information in the Data dictionary? The following information is directly taken from the Data dictionary: Information on fields displayed with

Define entity integrity and referential integrity, Define entity integrity ...

Define entity integrity and referential integrity.  How does SQL allow specification of  these? Ans: Entity Integrity Rule- If the attribute A of relation R is a prime attribut

Database for online assignment system, i want to database for online assign...

i want to database for online assignment submission system

What are called multilevel indices, What are called multilevel indices? ...

What are called multilevel indices? Indices with two or more levels are known as multilevel indices.

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