# mongoc_find_and_modify_opts_set_flags()

## Synopsis

    bool
    mongoc_find_and_modify_opts_set_flags (
       mongoc_find_and_modify_opts_t *opts,
       const mongoc_find_and_modify_flags_t flags);

## Parameters

- `opts`: A mongoc_find_and_modify_opts_t.

- `flags`: .

## Description

Adds one or more flags to the builder.

MONGOC_FIND_AND_MODIFY_NONE | Default. Doesn’t add anything to the builder.
MONGOC_FIND_AND_MODIFY_REMOVE | Will instruct find_and_modify to remove the matching document.
MONGOC_FIND_AND_MODIFY_UPSERT | Update the matching document or, if no document matches, insert the document.
MONGOC_FIND_AND_MODIFY_RETURN_NEW | Return the resulting document.

## Returns

Returns Returns `true` if it successfully added the option to the builder, otherwise `false` and logs an error.

## Setting flags

flags.c

    void
    fam_flags (mongoc_collection_t *collection)
    {
       mongoc_find_and_modify_opts_t *opts;
       bson_t reply;
       bson_error_t error;
       bson_t query = BSON_INITIALIZER;
       bson_t *update;
       bool success;

       /* Find Zlatan Ibrahimovic, the striker */
       BSON_APPEND_UTF8 (&query, "firstname", "Zlatan");
       BSON_APPEND_UTF8 (&query, "lastname", "Ibrahimovic");
       BSON_APPEND_UTF8 (&query, "profession", "Football player");
       BSON_APPEND_INT32 (&query, "age", 34);
       BSON_APPEND_INT32 (
          &query, "goals", (16 + 35 + 23 + 57 + 16 + 14 + 28 + 84) + (1 + 6 + 62));

       /* Add his football position */
       update = BCON_NEW ("$set", "{", "position", BCON_UTF8 ("striker"), "}");

       opts = mongoc_find_and_modify_opts_new ();

       mongoc_find_and_modify_opts_set_update (opts, update);

       /* Create the document if it didn't exist, and return the updated document */
       mongoc_find_and_modify_opts_set_flags (
          opts, MONGOC_FIND_AND_MODIFY_UPSERT | 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 (&query);
       mongoc_find_and_modify_opts_destroy (opts);
    }

Outputs:

    {
       "lastErrorObject" : {
          "updatedExisting" : false,
          "n" : 1,
          "upserted" : {"$oid" : "56562a99d13e6d86239c7b00"}
       },
                           "value" : {
                              "_id" : {"$oid" : "56562a99d13e6d86239c7b00"},
                              "age" : 34,
                              "firstname" : "Zlatan",
                              "goals" : 342,
                              "lastname" : "Ibrahimovic",
                              "profession" : "Football player",
                              "position" : "striker"
                           },
                                     "ok" : 1
    }