Canonical Functions

The ODBC specification supports various SQL functions that can be executed in a canonical method. For more information about passing the canonical form through a gateway without modification, see the comments in the SAMP.RC file. The Open Data Services ODBC driver supports a limited capability for parsing and converting the canonical form into a DBMS-specific format. The IDS_AUX_FUN_PINFO strings drive the parser/converter. The comments in the SAMP.RC file specify the string format.

The major restriction in the Open Data Services ODBC driver converter is that parameters cannot be duplicated or reordered. There is one string for each ODBC canonical function. If the gateway does not support the canonical form and the string is empty, the appropriate bit in the value of the SQL_xxxx_FUNCTIONS string must be zero, meaning that the canonical function is not supported.

If the canonical CONVERT function is supported, the values of the SQL_CONVERT_xxxx strings must correspond to the set of conversions supported for that datatype. See SQLGetInfo in the Microsoft ODBC 2.0 Programmer's Reference and SDK Guide for more information.