Bewerken

Delen via

SQL-92 CAST Function

  • Artikel

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) /* SQL92

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, the CAST function is supported.

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