A valid result id returned by sesam_query().
The column index is zero-based, not one-based as in SESAM.
Returns the name of a field in the result set, or
FALSE on error.
For "immediate" queries, or for dynamic columns, an empty string is returned.
|sesam_field_array(). It provides an easier interface to access the column names and types, and allows for detection of "multiple fields".|