After calling sesam_query() with a "select type" query, this function gives you the number of columns in the result.
For "immediate" statements, the value zero is returned. The SESAM "multiple field" columns count as their respective dimension, i.e., a three-column "multiple field" counts as three columns.
A valid result id returned by sesam_query().
Returns an integer describing the total number of columns (aka. fields) in
the current result_id result set or