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.
Note
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 | +---------+