SQLGetStmtOption Mapping

When an application calls SQLGetStmtOption to an ODBC 3.x driver that does not support it, the call to:

SQLGetStmtOption(hstmt, fOption, pvParam)

will result in:

If fOption indicates an ODBC-defined statement option that returns a string, then the Driver Manager calls:
```
SQLGetStmtAttr(StatementHandle, Attribute, 
                    ValuePtr, BufferLength, NULL)
```
If fOption indicates an ODBC-defined statement option that returns a 32-bit integer value, then the Driver Manager calls:
```
SQLGetStmtAttr(StatementHandle, Attribute, ValuePtr, 0, NULL)
```

If fOption indicates a driver-defined statement option, then the Driver Manager calls:

SQLGetStmtAttr(StatementHandle, Attribute, 
                    ValuePtr, BufferLength, NULL)

In these three cases, the StatementHandle argument is set to the value in hstmt, the Attribute argument is set to the value in fOption, and the ValuePtr argument is set to the same value as pvParam.

For ODBC-defined string connection options, the Driver Manager sets the BufferLength argument in the call to SQLGetConnectAttr to the predefined maximum length (SQL_MAX_OPTION_STRING_LENGTH); for a non-string connection option, BufferLength is set to 0.

The SQL_GET_BOOKMARK statement option has been deprecated in ODBC 3.x. For an ODBC 3.x driver to work with ODBC 2.x applications that use SQL_GET_BOOKMARK, it must support it. For an ODBC 3.x driver to work with ODBC 2.x applications, it must support setting SQL_USE_BOOKMARKS to SQL_UB_ON, and should expose fixed-length bookmarks. If an ODBC 3.x driver supports only variable-length bookmarks, not fixed-length bookmarks, then it must return SQLSTATE HYC00 (Optional feature not implemented) if an ODBC 2.x application attempts to set SQL_USE_BOOKMARKS to SQL_UB_ON.

For an ODBC 3.x driver, the Driver Manager no longer checks to see whether Option is in between SQL_STMT_OPT_MIN and SQL_STMT_OPT_MAX, or is greater than SQL_CONNECT_OPT_DRVR_START. The driver must check this.