CAST function [Data type conversion]

Returns the value of an expression converted to a supplied data type.

CAST ( expression AS data type )

The following function ensures a string is used as a date:

CAST( '2000-10-31' AS DATE )

The value of the expression 1 + 2 is calculated, and the result cast into a single-character string, the length the data server assigns:

CAST( 1 + 2 AS CHAR )

You can use the CAST function to shorten strings:

SELECT CAST( lname AS CHAR(5) ) FROM customer

If you do not indicate a length for character string types, Sybase IQ chooses an appropriate length. If neither precision nor scale is specified for a DECIMAL conversion, the database server selects appropriate values.

If neither precision nor scale is specified for the explicit conversion of NULL to NUMERIC, the default is NUMERIC(1,0). For example,

SELECT CAST( NULL AS NUMERIC ) A,
       CAST( NULL AS NUMERIC(15,2) ) B

is described as:

A NUMERIC(1,0)
B NUMERIC(15,2)