MySQL LOG2() Function

The MySQL LOG2() function returns the base-2 logarithm of a given number. In special cases it returns the following:

If the number is less than or equal to 0, then NULL is returned.

Syntax

LOG2(number)

Parameters

number Required. Specify the number. Must be greater than 0.

Return Value

Returns the base-2 logarithm of a given number.

Example 1:

The example below shows the usage of LOG2() function.

mysql> SELECT LOG2(1);
Result: 0

mysql> SELECT LOG2(1.5);
Result: 0.5849625007211562

mysql> SELECT LOG2(2);
Result: 1

mysql> SELECT LOG2(5);
Result: 2.321928094887362

mysql> SELECT LOG2(10);
Result: 3.3219280948873626

mysql> SELECT LOG2(0);
Result: NULL

Example 2:

Consider a database table called Sample with the following records:

Data	x
Data 1	0.5
Data 2	1
Data 3	5
Data 4	10
Data 5	50

The statement given below can be used to calculate the base-2 logarithm of column x.

SELECT *, LOG2(x) AS LOG2_Value FROM Sample;

This will produce the result as shown below:

Data	x	LOG2_Value
Data 1	0.5	-1
Data 2	1	0
Data 3	5	2.321928094887362
Data 4	10	3.3219280948873626
Data 5	50	5.643856189774724

❮ MySQL Functions