If a statement passed to
mysql_stmt_prepare() is one
that produces a result set,
returns the result set metadata in the form of a pointer to a
MYSQL_RES structure 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, such as:
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 18.104.22.168, “mysql_stmt_fetch()”.