MySQL in a Nutshell, 2nd Edition

Name

LOG()

Synopsis

LOG(number[, base])

This function returns the logarithm of the first argument to the base indicated by the second argument. This is the same as using LOG(number)/LOG(base). If the function is called with only the first argument, its natural logarithm is returned; the function is equivalent to LN in that case. Here is an example:

SELECT LOG(5,4);

+------------+
|   LOG(5,4) |
+------------+
| 1.16096405 |
+------------+