Description of to_number.gif follows
Description of the illustration ''to_number.gif''


TO_NUMBER converts expr to a value of NUMBER data type. The expr can be a number value of CHAR, VARCHAR2, NCHAR, NVARCHAR2, BINARY_FLOAT, or BINARY_DOUBLE data type.

  • If you specify an expr of CHAR, VARCHAR2, NCHAR, or NVARCHAR2 data type, then you can optionally specify the format model fmt.

  • If you specify an expr of BINARY_FLOAT or BINARY_DOUBLE data type, then you cannot specify a format model because a BINARY_FLOAT or BINARY_DOUBLE can be interpreted only by its internal representation.

Refer to "Format Models" for information on format models.

The 'nlsparam' argument in this function has the same purpose as it does in the TO_CHAR function for number conversions. Refer to TO_CHAR (number) for more information.

This function does not support CLOB data directly. However, CLOBs can be passed in as arguments through implicit data conversion.

See Also:

"Data Type Comparison Rules" for more information.


The following examples convert character string data into a number:

UPDATE employees SET salary = salary + 
   TO_NUMBER('100.00', '9G999D99')
   WHERE last_name = 'Perkins';
SELECT TO_NUMBER('-AusDollars100','L9G999D99',
     NLS_CURRENCY            = ''AusDollars''
   ') "Amount"