MySQL LOG2() Function

 The LOG2() function in MySQL is used to calculate the base-2 logarithm of a given number. This is particularly useful when dealing with binary-based calculations or when you need to determine how many times a number must be multiplied by 2 to reach a given value.

Syntax:

LOG2(number)

Parameters:

• number: The value for which you want to calculate the base-2 logarithm. It must be a positive number (greater than 0).

Returns:

• The base-2 logarithm of the input number.
• NULL if the input is less than or equal to 0.

Example Queries:

Example 1: Basic usage

SELECT LOG2(16);

Output: 4
Explanation: $2^4 = 16$.

Example 2: Non-integer input

SELECT LOG2(10);

Output: Approximately 3.3219280949
Explanation: $2^{3.3219280949} \approx 10$.

Example 3: Invalid input

SELECT LOG2(-5), LOG2(0);

Output: NULL, NULL
Explanation: The function returns NULL because the input values are non-positive.

Example 4: Using with other columns

If you have a table numbers with a column value, you can calculate the base-2 logarithm for each row:

SELECT value, LOG2(value) AS log_base_2
FROM numbers;

Notes:

• Ensure that the input values are greater than 0 to avoid NULL results.
• The LOG2() function is often used in data analysis tasks where binary computations or scaling are involved.

Let me know if you'd like further examples or have questions!