Sample usage
IFNULL(Discount, 0)
Syntax
IFNULL(input_expression, null_result)
Parameters
input_expression
The expression to evaluate. You can use any valid expression as the input_expression.
null_result
The result to return if input_expression is null. If input_expression is not null, IFNULL returns the input_expression. You can use any valid expression as the input_expression.
Example
Suppose you want to calculate the average discount given to your customers, including orders that received no discount, and you know that your application sometimes represents "no discount" as null rather than 0.
The formula AVG(Discount) won't include null discounts. You'll need to convert those nulls to zero. To do this, create a new field called, for example, Discount No Nulls:
IFNULL(Discount, 0)
This formula can be read, "If the Discount field is null, return 0, otherwise return Discount."
You can then calculate the average discount including orders with no discount: