The SQL LOG function is used to calculate the natural logarithm of a given numeric expression. The natural logarithm of a number is the logarithm to the base e, where e is a mathematical constant that is approximately equal to 2.71828.
Syntax
The syntax of the LOG function in SQL is as follows:
LOG(numeric_expression)
Here, the numeric_expression parameter is the value for which we want to calculate the natural logarithm.
Example
For example, suppose we have a table employees with the following data:
| id | name | salary |
|---|---|---|
| 1 | Alice | 50000 |
| 2 | Bob | 60000 |
| 3 | Claire | 70000 |
To calculate the natural logarithm of the salary column, we can use the following SQL query:
SELECT LOG(salary) FROM employees;
This will return the following result:
| LOG(salary) |
|---|
| 10.81978 |
| 11.00210 |
| 11.15625 |
The result shows the natural logarithm of each salary value in the table.
It’s worth noting that the LOG function can also take an optional second parameter that specifies the base of the logarithm. For example, to calculate the logarithm to the base 10, we can use the following syntax:
LOG(numeric_expression, 10)
In summary, the SQL LOG function is a useful tool for calculating the natural logarithm of a given numeric expression.