MySQL LN() Function – Return the Natural Logarithm of a Number

In MySQL, the LN() function returns the natural logarithm of a specified value.

You provide the specified value as an argument when calling the function.

This function is synonymous with the single-argument syntax of the LOG() function.

Syntax

The syntax goes like this:

LN(X)

Where X is the value for which you want the natural logarithm returned.

If X is less than or equal to 0.0E0, the function returns NULL and a warning is generated.

Here’s a basic example to demonstrate how this function works.

SELECT LN(2);

Result:

+--------------------+
| LN(2)              |
+--------------------+
| 0.6931471805599453 |
+--------------------+

And here’s another example using a different value.

SELECT LN(0.1);

Result:

+---------------------+
| LN(0.1)             |
+---------------------+
| -2.3025850929940455 |
+---------------------+

Here’s an example of passing in a negative value.

SELECT LN(-1);

Result:

+--------+
| LN(-1) |
+--------+
|   NULL |
+--------+

This example returns a NULL value because the argument provided is less than 0.0E0.

Here’s an example of passing in zero as the argument (we get the same result as the previous example).

SELECT LN(0);

Result:

+-------+
| LN(0) |
+-------+
|  NULL |
+-------+

You can also pass in expressions like this:

SELECT LN(1+1);

Result:

+--------------------+
| LN(1+1)            |
+--------------------+
| 0.6931471805599453 |
+--------------------+