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LOG
Returns the logarithm of the given argument in the given base. If only one argument is given, this function returns the “natural” logarithm to base e.
Syntax
LOG ( base, number )
LOG ( number )
Arguments
- base: the base of the logarithm.
- number: the number to take the logarithm of.
Info
log(n) is an alias for ln(n).
log(b, n) is equivalent to ln(n) / ln(b).
Return Type
Float or double. If number is less than or equal to 0, or if base is non-positive or 1, returns NULL.
Examples
select log(2, 16);
+------------+
| log(2, 16) |
+------------+
| 4 |
+------------+
select log(2, 1234);
+-------------------+
| log(2, 1234) |
+-------------------+
| 10.26912667914942 |
+-------------------+
select log(1234);
+--------------------+
| log(1234) |
+--------------------+
| 7.1180162044653335 |
+--------------------+
select ln(1234);
+--------------------+
| ln(1234) |
+--------------------+
| 7.1180162044653335 |
+--------------------+
select log(10, 1000), ln(1000) / ln(10);
+--------------------+--------------------+
| log(10, 1000) | ln(1000) / ln(10) |
+--------------------+--------------------+
| 2.9999999999999996 | 2.9999999999999996 |
+--------------------+--------------------+
select log(-9);
+---------+
| log(-9) |
+---------+
| NULL |
+---------+
