How To Check For NULL Values Correctly In SQL

MenolMay 17, 2012Database-Concepts, Oracle, SQL Servercheck-for-NULL-correctly-in-sql, checking for Null values, SQL, SQL Server

SELECT PatientId FROM Patients WHERE Surname = NULL  --  THIS IS WRONG
SELECT PatientId FROM Patients WHERE Surname is NULL  --  THIS IS CORRECT

SELECT PatientId FROM Patients WHERE Surname != NULL  --  THIS IS WRONG
SELECT PatientId FROM Patients WHERE Surname is not NULL  --  THIS IS CORRECT

2 thoughts on “How To Check For NULL Values Correctly In SQL”

Tom says:

May 17, 2012 at 11:32 pm

Hello! Great blog, I love it!

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Bijan says:

June 13, 2012 at 4:20 am

This is the correct blog for everyone who wants to learn about this subject. You realize much its virtually hard to argue with you (not too I actually would want…HaHa). You definitely put a new spin on a topic thats been discussing for years. Excellent stuff, only great!

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