PLSQL | LN Function

The LN function is an inbuilt function in PLSQL which is used to return the natural logarithm of a given input number. The natural logarithm of a number is the logarithm of that number to the base e, where e is the mathematical constant approximately equal to 2.718. This is written using the notation lnx and also some time as logex. Syntax:

LN(number) 

Parameters Used: This function accept a parameter number which is the numeric value used to calculate the natural logarithm. This number should must be greater than 0. Return Value: This function returns the natural logarithm of a given input numeric value. Supported Versions of Oracle/PLSQL:

1. Oracle 12c
2. Oracle 11g
3. Oracle 10g
4. Oracle 9i
5. Oracle 8i

Let's see some examples which illustrate the LN function: Example-1:

DECLARE 
   Test_Number number := 20;
   
BEGIN 
   dbms_output.put_line(LN(Test_Number number)); 
   
END;  

Output:

2.99573227355399

In the above example, 20 is the numeric value whose natural logarithm value is 2.99573227355399 Example-2:

DECLARE 
   Test_Number number := 25;
   
BEGIN 
   dbms_output.put_line(LN(Test_Number number)); 
   
END; 

Output:

3.2188758248682

In the above example, 25 is the numeric value whose natural logarithm value is 3.2188758248682 Example-3:

DECLARE 
   Test_Number number := 100.5;
   
BEGIN 
   dbms_output.put_line(LN(Test_Number number)); 
   
END; 

Output:

4.61015772749913

In the above example, 100.5 is the numeric value whose natural logarithm value is 4.61015772749913 Advantage: This function is used to find out the natural logarithm of a given input number.