Interview Questions Answers.ORG
Interviewer And Interviewee Guide
Interviews
Quizzes
Home
Quizzes
Interviews DB Oracle Interviews:Concepts and ArchitectureData AccessDatabase ArchitectureDatabase ManagementDatabase Security OracleDistributed ProcessingFlexfieldForms ReportsGeneral OracleMemory ManagementMTO-SAP Financial AccountingOCIOracle AOLOracle AROracle Backup RecoveryOracle D2KOracle DatabaseOracle Database DeveloperOracle DB OptimizationOracle DBAOracle DeveloperOracle ETLOracle Forms 3.0Oracle Forms 4.0Oracle GLOracle PL-SQLOracle RMANOracle ScenariosOracle SecurityOracle SQLOracle System ArchitectureOracle Technology Network (OTN)Programmatic ConstructsRAC (Real Application Clusters)SQL Plus
Copyright © 2018. All Rights Reserved
Oracle Database Interview Question:
What Is NULL value in Oracle?
Submitted by: AdministratorNULL is a special value representing "no value" in all data types. NULL can be used on in operations like other values. But most operations has special rules when NULL is involved. The tutorial exercise below shows you some examples:
SET NULL 'NULL'; -- Make sure NULL is displayed
SELECT NULL FROM DUAL;
N
-
N
U
L
L
SELECT NULL + NULL FROM DUAL;
NULL+NULL
----------
NULL
SELECT NULL + 7 FROM DUAL;
NULL+7
----------
NULL
SELECT NULL * 7 FROM DUAL;
NULL*7
----------
NULL
SELECT NULL || 'A' FROM DUAL;
N
-
A
SELECT NULL + SYSDATE FROM DUAL;
NULL+SYSD
---------
NULL
Submitted by: Administrator
SET NULL 'NULL'; -- Make sure NULL is displayed
SELECT NULL FROM DUAL;
N
-
N
U
L
L
SELECT NULL + NULL FROM DUAL;
NULL+NULL
----------
NULL
SELECT NULL + 7 FROM DUAL;
NULL+7
----------
NULL
SELECT NULL * 7 FROM DUAL;
NULL*7
----------
NULL
SELECT NULL || 'A' FROM DUAL;
N
-
A
SELECT NULL + SYSDATE FROM DUAL;
NULL+SYSD
---------
NULL
Submitted by: Administrator
Copyright 2007-2024 by Interview Questions Answers .ORG All Rights Reserved.
https://InterviewQuestionsAnswers.ORG.
https://InterviewQuestionsAnswers.ORG.