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  • SQL ISNULL()
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  1. Data Query Language

SQL ISNULL Functions

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Last updated 6 years ago

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SQL ISNULL()

Look at the following "Products" table:

Suppose that the "UnitsOnOrder" column is optional, and may contain NULL values.

Look at the following SELECT statement:

SELECT ProductName, UnitPrice * (UnitsInStock + UnitsOnOrder)
FROM Products;

In the example above, if any of the "UnitsOnOrder" values are NULL, the result will be NULL.

Example

SELECT ProductName, UnitPrice * (UnitsInStock + ISNULL(UnitsOnOrder, 0))
FROM Products

The SQL Server function lets you return an alternative value when an expression is NULL:

ISNULL()