LOG functions
LOG: If called with one parameter, this function returns the natural logarithm of x. If x is less than or equal to 0.0E0, the function returns NULL.
LOG2: Returns the base-2 logarithm of x. If x is less than or equal to 0.0E0, the function returns NULL.
LOG10: Returns the base-10 logarithm of x. If x is less than or equal to 0.0E0, the function returns NULL.
LN: Returns the natural logarithm of x; that is, the base-e logarithm of x. If x is less than or equal to 0.0E0, the function returns NULL.
Syntax
LOG(x)
LOG(b, x)
LOG2(x)
LOG10(x)
LN(x)
Examples
SELECT LOG(2);
+--------------------+
| LOG(2) |
+--------------------+
| 0.6931471805599453 |
+--------------------+
SELECT LOG(-2);
+---------+
| LOG(-2) |
+---------+
| NaN |
+---------+
SELECT LOG(2, 65536);
+---------------+
| LOG(2, 65536) |
+---------------+
| 16 |
+---------------+
SELECT LOG2(65536);
+-------------+
| LOG2(65536) |
+-------------+
| 16 |
+-------------+
SELECT LOG10(100);
+------------+
| LOG10(100) |
+------------+
| 2 |
+------------+
SELECT LN(2);
+--------------------+
| LN(2) |
+--------------------+
| 0.6931471805599453 |
+--------------------+