Purpose
TO_NUMBER converts char, a value of CHAR or VARCHAR2 datatype containing a number in the format specified by the optional format model fmt, to a value of NUMBER datatype.
Examples
UPDATE emp SET sal = sal +
TO_NUMBER('100.00', '9G999D99')
WHERE ename = 'BLAKE';
The 'nlsparams' string in this function has the same purpose as it does in the TO_CHAR function for number conversions.
