bool
mongoc_find_and_modify_opts_set_fields (mongoc_find_and_modify_opts_t *opts,


                                        const bson_t *fields);

void
fam_fields (mongoc_collection_t *collection)
{


   mongoc_find_and_modify_opts_t *opts;


   bson_t fields = BSON_INITIALIZER;


   bson_t *update;


   bson_t reply;


   bson_error_t error;


   bson_t query = BSON_INITIALIZER;


   bool success;


   /* Find Zlatan Ibrahimovic */


   BSON_APPEND_UTF8 (&query, "lastname", "Ibrahimovic");


   BSON_APPEND_UTF8 (&query, "firstname", "Zlatan");


   /* Return his goal tally */


   BSON_APPEND_INT32 (&fields, "goals", 1);


   /* Bump his goal tally */


   update = BCON_NEW ("$inc", "{", "goals", BCON_INT32 (1), "}");


   opts = mongoc_find_and_modify_opts_new ();


   mongoc_find_and_modify_opts_set_update (opts, update);


   mongoc_find_and_modify_opts_set_fields (opts, &fields);


   /* Return the new tally */


   mongoc_find_and_modify_opts_set_flags (opts, MONGOC_FIND_AND_MODIFY_RETURN_NEW);


   success = mongoc_collection_find_and_modify_with_opts (collection, &query, opts, &reply, &error);


   if (success) {


      char *str;


      str = bson_as_canonical_extended_json (&reply, NULL);


      printf ("%s\n", str);


      bson_free (str);


   } else {


      fprintf (stderr, "Got error: \"%s\" on line %d\n", error.message, (int) (__LINE__));


   }


   bson_destroy (&reply);


   bson_destroy (update);


   bson_destroy (&fields);


   bson_destroy (&query);


   mongoc_find_and_modify_opts_destroy (opts);
}

{


   "lastErrorObject"


      : {"updatedExisting" : true, "n" : 1},


        "value"


        : {"_id" : {"$oid" : "56562a99d13e6d86239c7b00"}, "goals" : 343},


          "ok" : 1
}