Oracle - CAST Function - Convert One Built-in Data Type into Another

CAST function converts one built-in data type into another built-in data type with the specified precision and length.

Quick Example:

Convert a string value to NUMBER leaving 2 digits after the decimal point:

   SELECT CAST('245.211' AS NUMBER(5,2)) FROM dual;
   -- Result: 245.21

You can use CAST function to convert a string value to number, and round it to the specified number of decimal digits:

   SELECT CAST('245.205' AS NUMBER(5,2)) FROM dual;
   -- Result: 245.21 (note that the value is rounded, not truncated to 245.20)

Using CAST you can round numbers too:

   SELECT CAST(245.205 AS NUMBER(5,2)) FROM dual;
   -- Result: 245.21

• Reference and Articles
• Functions

Oracle 11g Release 2 SQL Language Reference

• CAST Function