The TO_NUMBER function converts a character string of type CHAR or VARCHAR2 into a number.
The Syntax for the TO_NUMBER Function
TO_NUMBER(character_string, format, NLS_Params)
After the format mask are several possible NLS parameters:
NLS_NUMERIC_CHARACTERS -- Specifies characters to use for group separators and the decimal point.
NLS_CURRENCY -- Specifies the local currency.
NLS_ISO_CURRENCY -- Character(s) to represent the ISO currency symbol.
You can provide an optional format string to indicate the format of x.
ParameterFormat Examples
9999
00999 9990
.999.99
,9,999
$$999
BB9.99
CC999
D9D99
EEEE9.99EEEE
FMFM90.9
G9G999
LL999
MI999MI
PR999PR
RN rnRN rn
SS999 999S
TMTM
UU999
V99V99
XXXXX
The following example converts the string 97.13 to a number using TO_NUMBER():
SQL>
SQL> SELECT TO_NUMBER('97.13') FROM dual;
TO_NUMBER('97.13')
------------------
97.13
SQL>