unsigned int mysql_stmt_field_count(MYSQL_STMT * stmt);
stmt - a statement handle, which was previously allocated by mysql_stmt_init().
stmt
Returns the number of fields in a result set of a prepared statement.
The number of fields will be available after calling mysql_stmt_prepare()
mysql_stmt_field_count() returns zero for UPSERT statements which don't produce a result set.
mysql_stmt_prepare()
mysql_stmt_param_count()