If a statement executed by
mysql_stmt_execute() is one
that produces a result set,
called after execution returns the result set metadata in the
form of a pointer to a
that can be used to process the meta information such as
number of fields and individual field information. This result
set pointer can be passed as an argument to any of the
field-based API functions that process result set metadata,
The result set structure should be freed when you are done
with it, which you can do by passing it to
mysql_free_result(). This is
similar to the way you free a result set obtained from a call
MYSQL_RES result structure.
NULL if no meta information exists for the
See the Example in Section 11.11, “mysql_stmt_fetch()”.