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?

What is the use of integrity constraints, What is the use of integrity cons...

What is the use of integrity constraints? Integrity constraints make sure that changes made to the database by authorized users do not result in a loss of data consistency. The

Give an example of operations from the functions of a bank, Give an example...

Give an example of Operations from the functions of a bank. For creation of a saving account, you can write: bank::: create -savings-account (customer)->account. For oper

Define 1 nf normal form, 1 NF Normal Form The domain of attribute must...

1 NF Normal Form The domain of attribute must add only atomic (simple, indivisible) values First normal form (Minimal Form or 1NF) is a normal form need in database normalizat

Explain about data independence, Data Independence This brings us to ou...

Data Independence This brings us to our next topic: data independence. It is the property of the database which tries to make sure that if we make any change in any level of sc

Identification of concurrency, Identification of concurrency Identifica...

Identification of concurrency Identification of concurrency: Dynamic model identifies concurrency. Two objects are said to be parallel (concurrent) if they can receive events a

Database system design and Implementation, Consider a typical sales invoice...

Consider a typical sales invoice that would include the following information. Design a single table to hold all of the information required to store an invoice including this info

Define the terms entity type and entity set, Define the terms i) Entity typ...

Define the terms i) Entity type ii) Entity set Entity type: An entity type describes a collection of entities that have the similar attributes. Entity set: The set of all en

Give detail description on transactions, Give detail description on Transac...

Give detail description on Transactions. - Using transactions we can group all SQL commands into a single unit. - Transaction begins with some task and finishes only when a

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

Explain embedding sql statements, Question 1 Explain the functions of t...

Question 1 Explain the functions of the following Storage Manager Buffer Manager Transaction Manager 2 Discuss about system catalog in a relational DBMS 3

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages