/*
 * call-seq:
 *    res.num_fields()
 *
 * Returns the number of fields (columns) in the query result.
 *
 * Similar to <tt>res.result[0].length</tt> (but faster).
 */
static VALUE
pgresult_num_fields(obj)
  VALUE obj;
{
  int n;

  n = PQnfields(get_pgresult(obj));
  return INT2NUM(n);
}