CAST function [Data type conversion]

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

The CAST, CONVERT, HEXTOINT, and INTTOHEX functions can be used to convert to and from hexadecimal values. For more information on using these functions, see Converting to and from hexadecimal values.

Syntax

CAST( expression AS datatype )

Parameters

Returns

Remarks

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

If you use the CAST function to truncate strings, the string_rtruncation database option must be set to OFF; otherwise, there will be an error. It is recommended that you use the LEFT function to truncate strings.

Standards and compatibility

SQL/2008 The CAST function is a core feature of the SQL/2008 standard. However, in SQL Anywhere CAST supports a number of data type conversions that are not permitted by the SQL standard. For example, in SQL Anywhere you can CAST an integer value to a DATE type, whereas in the SQL standard this type conversion is not permitted. For more information, see Data type conversions.

Example

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

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

The value of the expression 1 + 2 is calculated, and the result is then cast into a single-character string.

SELECT CAST( 1 + 2 AS CHAR );

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