SQL-92 Cast Function

The CAST function defined in SQL-92 is equivalent to the CONVERT function defined in ODBC. The syntax of the equivalent functions is as follows:

{ fn CONVERT (value-exp, data-type)} /* ODBC

CAST (value-exp AS data-type) /* SQL-92

The SQL-92 CAST function mandates which data types can be converted to which other data types. (For more information, see the SQL-92 specification.) The CAST function is supported at the FIPS Transitional level.

An application can determine support for the CAST function as follows:

1 Call SQLGetInfo with the SQL_SQL_CONFORMANCE information type. If the return value for the information type is SQL_SC_FIPS127_2_TRANSITIONAL, SQL_SC_SQL92_INTERMEDIATE, or SQL_SC_SQL92_FULL, then the CAST function is supported.

2 If the return value of the SQL_SQL_CONFORMANCE information type is SQL_SC_ENTRY_LEVEL or 0, then call SQLGetInfo with the SQL_SQL92_VALUE_EXPRESSIONS information type. If the SQL_VE_CAST bit is set, then the CAST function is supported.