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MySQL IFNULL Operator

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The MySQL IFNULL is used to replace the NULLs with custom values or custom text. This is very useful to replace the annoying NULLS with custom information.

In this article, we will show you, How to use the IFNULL with example

MySQL IFNULL Syntax

The basic syntax behind this MySQL IFNULL is as follows:

SELECT IFNULL(expression1, expression2)

This operator accepts two arguments, if the first value (expression 1) is not null then it will be returned. If the expression1 value is NULL then expression2 is returned

MySQL IFNULL Operator Example 1

In this example query, we will show you, the simple IFNULL operator examples. Here, the first statement returns 10 because 10 is Not Null. The second statement returns 5 because first argument is Null. Within the last statement, 1/0 is a NULL so 5 and Wrong was returned.

SELECT IFNULL(10, 5);

SELECT IFNULL(NULL, 5);

SELECT IFNULL(1/0, 5), IFNULL(1/0, 'Wrong');

OUTPUT

MySQL IFNULL Operator 1

MySQL IFNULL Example 2

We are using this Employee Details table for the IFNULL operator demonstration. The below screenshot shows you the data inside this table

MySQL IFNULL Operator 2

In this example query, we used IFNULL operator on Middle Name. If the Middle name is Null then it will replace with ‘No Middle Name’ as Name1, and ‘Tutorial Gateway’ as Name2. Otherwise, it returns the Middle Name.

SELECT 
     CustomerKey,
     FirstName, 
     IFNULL(MiddleName, 'No Middle Name') AS Name1,
     IFNULL(MiddleName, 'Tutorial gateway') AS Name2,
     LastName,
     YearlyIncome,
     Phone,
     Office,
     Mobile
 FROM `MySQL Tutorial`.EmployeeDetails;

OUTPUT

MySQL IFNULL Operator 3

This time, we are using this IFNULL on Middle Name, Phone, Office and Middle columns. If there is any Null values in the phone numbers then replace them with 0.

SELECT 
     CustomerKey,
     FirstName, 
     IFNULL(MiddleName, 'Tutorial gateway') AS MName,
     LastName,
     YearlyIncome,
     IFNULL(Phone, 0),
     IFNULL(Office, 0),
     IFNULL(Mobile, 0)
 FROM `MySQL Tutorial`.EmployeeDetails;

OUTPUT

MySQL IFNULL Operator 4

Until now, we are using this IFNULL to replace the column NULL values with custom text. However, you can also use another column value as the replacement value. In this example, IFNULL(Phone, Office) means, if there are any nulls in Phone column then they will be replace by the corresponding office numbers.

SELECT 
     CustomerKey,
     FirstName, 
     IFNULL(MiddleName, 'Tutorial gateway') AS MName,
     LastName,
     YearlyIncome,
     IFNULL(Phone, Office),
     IFNULL(Office, Phone),
     IFNULL(Mobile, Phone)
 FROM `MySQL Tutorial`.EmployeeDetails;

OUTPUT

MySQL IFNULL Operator 5

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