SQL LN() function

LN() function

SQL LN() function returns the natural logarithm of n, where n is greater than 0 and its base is a number equal to approximately 2.71828183.



DB2, PostgreSQL, and Oracle

All of above platforms support the SQL syntax of LN().

MySQL and SQL Server

If you are using above two platforms, use LOG() instead.


Name Description
expression An expression which is a float or can be converted to a float.

SQL LN() function: Visual presentation

SQL LN() function


To get the natural logarithm of 65 from the DUAL table, the following SQL statement can be used:

-- This SQL statement calculates the natural logarithm of the number 65 and renames the result as 'natural_log of 65', selecting the result from the 'dual' table.
SELECT LN(65) "natural_log of 65" 
-- SELECT statement retrieves data from the database
-- LN() function calculates the natural logarithm of the specified number
-- In this case, LN(65) calculates the natural logarithm of 65
FROM dual;
-- Specifies the 'dual' table, a special one-row, one-column table present in Oracle database
-- The 'dual' table is often used for performing calculations or returning single results in SQL queries


  • This SQL query is straightforward, as it's only a single statement.
  • The purpose of this query is to calculate the natural logarithm of the number 65.
  • LN() is a mathematical function that calculates the natural logarithm of a given number.
  • In this case, LN(65) will return the natural logarithm of 65, which is approximately 4.174387.
  • The "natural_log of 65" is an alias provided to the result of the calculation, making it easier to identify in the query result.
  • The 'dual' table is used here because it's a convenient way to execute single-row queries in Oracle SQL without needing to specify an actual table with data.


natural_log of 65

Note: Outputs of the said SQL statement shown here is taken by using Oracle Database 10g Express Edition.

Here is a slide presentation which covers the SQL arithmetic functions.

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