mongoc_find_and_modify_opts_set_fields man page

mongoc_find_and_modify_opts_set_fields ā€” mongoc_find_and_modify_opts_set_fields()

Synopsis

bool
mongoc_find_and_modify_opts_set_fields (mongoc_find_and_modify_opts_t *opts,
                                        const bson_t *fields);

Parameters

Description

Adds fields argument to the builder.

fields does not have to remain valid after calling this function.

Returns

Returns true if it successfully added the option to the builder, otherwise false.

Setting Fields

fields.c.INDENT 0.0

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, __LINE__);
   }

   bson_destroy (&reply);
   bson_destroy (update);
   bson_destroy (&fields);
   bson_destroy (&query);
   mongoc_find_and_modify_opts_destroy (opts);
}

Outputs:

{
   "lastErrorObject"
      : {"updatedExisting" : true, "n" : 1},
        "value"
        : {"_id" : {"$oid" : "56562a99d13e6d86239c7b00"}, "goals" : 343},
          "ok" : 1
}

Author

MongoDB, Inc

Info

Oct 12, 2017 1.8.1 MongoDB C Driver