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