how to use ln (natural log) function in oracle database query

The LN (natural log) function in Oracle SQL / PLSQL is used to return the natural logarithmic value of a number.

Syntax for the LOG function in Oracle SQL / PLSQL is:

SELECT LN(n)
FROM table_name;

n must be a positive number

Example 1:

SELECT LN(20)
FROM DUAL;

Will return “2.99573227355399”

Example 2:

SELECT LN(1)
FROM DUAL; 

Will return “0”