Microsoft SQL Server NULLs ISNULL()
Example
The IsNull() function accepts two parameters, and returns the second parameter if the first one is null.
Parameters:
- check expression. Any expression of any data type.
- replacement value. This is the value that would be returned if the check expression is null. The replacement value must be of a data type that can be implicitly converted to the data type of the check expression.
The IsNull() function returns the same data type as the check expression.
DECLARE @MyInt int -- All variables are null until they are set with values.
SELECT ISNULL(@MyInt, 3) -- Returns 3.
See also COALESCE, above
