Oracle PL/SQL/Numeric Math Functions/LN

LN: Returns natural logs, that is, logs with respect to base e

SQL>
SQL> -- create demo table
SQL> create table TestTable(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
  3    MyName             VARCHAR2(10 BYTE),
  4    MyDate             DATE,
  5    MyNumber           Number(8,2)
  6  )
  7  /
Table created.
SQL>
SQL>
SQL> insert into TestTable (ID, MyName, MyDate, MyNumber) values("1","Alison",to_date("19960711","YYYYMMDD"),12.12);
1 row created.
SQL> insert into TestTable (ID, MyName, MyDate, MyNumber) values("1","Alison",to_date("19970622","YYYYMMDD"),2.12);
1 row created.
SQL> insert into TestTable (ID, MyName, MyDate, MyNumber) values("1","Alison",to_date("19980513","YYYYMMDD"),22.1);
1 row created.
SQL> insert into TestTable (ID, MyName, MyDate, MyNumber) values("1","Alison",to_date("19990624","YYYYMMDD"),2.12);
1 row created.
SQL> insert into TestTable (ID, MyName, MyDate, MyNumber) values("1","Alison",to_date("20000415","YYYYMMDD"),2.1);
1 row created.
SQL>
SQL>
SQL> select * from TestTable
  2
SQL>
SQL>
SQL> --LN: Returns natural logs, that is, logs with respect to base e.
SQL> SELECT LN(MyNumber) FROM TestTable;
LN(MYNUMBER)
------------
  2.49485698
  .751416089
  3.09557761
  .751416089
  .741937345
SQL>
SQL>
SQL>
SQL>
SQL> drop table TestTable;

LN(x):Returns the natural logarithm of x

SQL> -- 
SQL>
SQL> --LN(x):Returns the natural logarithm of x.
SQL>
SQL> select LN(2.71828183) from dual;
LN(2.71828183)
--------------
             1
SQL>