Syntax

LN(X)

Description

Returns the natural logarithm of X; that is, the base-e logarithm of X. If X is less than or equal to 0, or NULL, then NULL is returned.

The inverse of this function is EXP().

Examples

SELECT LN(2);
+-------------------+
| LN(2)             |
+-------------------+
| 0.693147180559945 |
+-------------------+

SELECT LN(-2);
+--------+
| LN(-2) |
+--------+
|   NULL |
+--------+