log

Description

Calculates the logarithm of a number to a specified base (or radix). If the base is not specified, this function is equivalent to ln.

Syntax

log([base,] arg)

Parameters

• base: Optional. The base. Only DOUBLE data type is supported. If this parameter is not specified, this function is equivalent to ln.

NOTE

CelerData returns NULL if base is specified as a negative, 0, or 1.

• arg: The value whose logarithm you want to calculate. Only DOUBLE data type is supported.

NOTE

CelerData returns NULL if arg is specified as a negative or 0.

Return value

Returns a value of the DOUBLE data type.

Example

Example 1: Calculate the logarithm of 8 to the base 2.

mysql> select log(2,8);
+-----------+
| log(2, 8) |
+-----------+
|         3 |
+-----------+
1 row in set (0.01 sec)

Example 2: Calculate the logarithm of 10 to the base e (with the base not specified).

mysql> select log(10);
+-------------------+
| log(10)           |
+-------------------+
| 2.302585092994046 |
+-------------------+
1 row in set (0.09 sec)