LOG10 (Transact-SQL)
Returns the base-10 logarithm of the specified float expression.
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Transact-SQL Syntax Conventions
Syntax
LOG10 ( float_expression )
Arguments
- float_expression
Is an expression of type float or of a type that can be implicitly converted to float.
Return Types
float
Remarks
The LOG10 and POWER functions are inversely related to one another. For example, 10 ^ LOG10(n) = n.
Examples
A. Calculating the base 10 logarithm for a variable.
The following example calculates the LOG10 of the specified variable.
DECLARE @var float;
SET @var = 145.175643;
SELECT 'The LOG10 of the variable is: ' + CONVERT(varchar,LOG10(@var));
GO
Here is the result set.
The LOG10 of the variable is: 2.16189
(1 row(s) affected)
B. Calculating the result of raising a base-10 logarithm to a specified power.
The following example returns the result of raising a base-10 logarithm to a specified power.
SELECT POWER (10, LOG10(5));
Here is the result set.
-----------
5
(1 row(s) affected)