MONGOC_FIND_A...OPTS_SET_FLAGS(3)

✨ MONGOC_FIND_A...OPTS_SET_FLAGS(3) ✨

okay bestie, sit down, hydrate, and let's talk about libmongoc's mongoc_find_and_modify_opts_set_flags() — the little function that tells your find-and-modify builder what energy to bring 💅

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🌸 SYNOPSIS 🌸

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

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🎀 PARAMETERS 🎀

• opts — a mongoc_find_and_modify_opts_t. the builder babe herself 🫶
• flags — .

and yes, the official description for flags is literally just a period 😭 not me reading the source docs and finding a whole single dot. iykyk. moving on!!

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💖 DESCRIPTION 💖

so what this bad boy does is add one or more flags to the builder. that's it, that's the vibe. here's your flag menu, no cap 🍓

• MONGOC_FIND_AND_MODIFY_NONE — the default. doesn't add anything to the builder. it's giving "i'm just here so i won't get fined" ✨
• MONGOC_FIND_AND_MODIFY_REMOVE — will instruct find_and_modify to remove the matching document. bye bestie 👋 literally deleting them from existence 💀
• MONGOC_FIND_AND_MODIFY_UPSERT — update the matching document or, if no document matches, insert the document. so if they don't exist yet, we simply make them exist. main character energy 👑
• MONGOC_FIND_AND_MODIFY_RETURN_NEW — return the resulting document. not the old one, the new one. the glow-up version 🌈

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⭐ RETURNS ⭐

Returns Returns true if it successfully added the option to the builder, otherwise false and logs an error. (yes it really says "Returns Returns" twice — iconic of the docs honestly, we're keeping it, no edits 💅)

so real talk: true = slay, false = it logged an error, go read it 🙈

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🦋 SETTING FLAGS 🦋

here's flags.c, the whole vibe in code form:

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, (int)(__LINE__));
   }

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

and the output is giving:

{
   "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
}

look at that indentation situation. we don't fix it, we respect it 🧚 the upserted field ate, the ok : 1 is the cherry on top 🍓 (and yes, that goals math adds up to 342, the code did NOT come to play)

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👑 AUTHOR 👑

MongoDB, Inc — the founders of the whole situation 🫶

💜 COPYRIGHT 💜

2009-present, MongoDB, Inc.

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and that's the page bestie!! version 2.5.6, dated Oct 09, 2026 — libmongoc forever, mwah 💋✨