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Simple Trick Using ISNULL

Simple Trick Using ISNULL:

Step-1: Create Sample Student Table.

CREATE TABLE Student
(
Id INT IDENTITY(1,1) PRIMARY KEY,
StudentName VARCHAR(100) NOT NULL,
LivingLocation VARCHAR(100) NULL
)
Step-2 :Insert Some Sample Data

INSERT INTO Student
SELECT 'Rakesh','Hyderabad'
UNION ALL
SELECT 'Raju','Delhi'
UNION ALL
SELECT 'Madhu','Hyderabad'
UNION ALL
SELECT 'Naresh',NULL
UNION ALL
SELECT 'Venaktesh','Chennai'

Step-3 :Select Data from Student Table

SELECT * FROM Student









If we observe above data of student table we have student id 4 record LivingLocation is NULL.

Step -4 :Select Data from Student Table With Where Clause.

SELECT * FROM Student WHERE LivingLocation='Hyderabad'






In the above query we are included the where clause with LivingLocation is 'Hyderabad'

SELECT * FROM Student WHERE LivingLocation<>'Hyderabad'






In the above query we want data from Student Table whose LivingLocation is not equal to the 'Hyderabad' , but it is not selected the data whose id is '4' ,because of the id of '4' LivingLocation is NULL , but we need that record also in this situation we can we ISNULL function.

SELECT * FROM Student WHERE ISNULL(LivingLocation,'')<>'Hyderabad'




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Comments

  1. UnknownJanuary 28, 2015 at 4:29 AM

    Good one !!

    ReplyDelete
  2. UnknownJanuary 29, 2015 at 6:15 PM

    INSERT INTO Student
    VALUES('SHABARINADH','VIJAYAWADA')
    ,VALUES('Raju','Delhi')
    ,VALUES('Madhu','Hyderabad')
    ,VALUES('Naresh',NULL)
    ,VALUES('Venaktesh','Chennai')


    What about this?

    ReplyDelete
  3. AnonymousJanuary 29, 2015 at 11:05 PM

    INSERT INTO Student (StudentName,LivingLocation)
    VALUES('SHABARINADH','VIJAYAWADA'),
    ('Raju','Delhi'),
    ('Madhu','Hyderabad'),
    ('Naresh',NULL),
    ('Venaktesh','Chennai')

    ReplyDelete

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