Term: CAST

Definition:
The Oracle CAST function converts one datatype to another.

Example Usage:

SELECT cast( '22-Aug-2003' AS varchar2(30))

FROM dual;

This would convert the date ' 15-May-2010' into a varchar2(30) value.

Casting Built-In Datatypes
	from BINARY_FLOAT, BINARY_DOUBLE	from CHAR, VARCHAR2	fromNUMBER	from DATETIME / INTERVAL (Note 1)	fromRAW	from ROWID, UROWID (Note 2)	from NCHAR, NVARCHAR2
to BINARY_FLOAT, BINARY_DOUBLE	`X`	`X`	`X`	`—`	`—`	`—`	`X`
to CHAR, VARCHAR2	`X`	`X`	`X`	`X`	`X`	`X`	`—`
to NUMBER	`X`	`X`	`X`	`—`	`—`	`—`	`X`
to DATE, TIMESTAMP, INTERVAL	`—`	`X`	`—`	`X`	`—`	`—`	`—`
to RAW	`—`	`X`	`—`	`—`	`X`	`—`	`—`
to ROWID, UROWID	`—`	`X`	`—`	`—`	`—`	`Xa`	`—`
to NCHAR, NVARCHAR2	`X`	`—`	`X`	`X`	`X`	`X`	`X`

Note 1: Datetime/interval includes DATE, TIMESTAMP, TIMESTAMP WITH TIMEZONE, INTERVAL DAY TO SECOND, and INTERVAL YEAR TO MONTH.

Note 2: You cannot cast a UROWID to a ROWID if the UROWID contains the value of a ROWID of an index-organized table.