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LOG10 (Transact-SQL)

Returns the base-10 logarithm of the specified float expression.

Topic link iconTransact-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)