MONGOC_COLLECTION_REPLACE_ONE(3)

💅 MONGOC_COLLECTION_REPLACE_ONE 💅

okay bestie, welcome to libmongoc's very own mongoc_collection_replace_one — the function that's literally the "swap the whole doc out" girlie of the collection world. she's giving ✨glow-up✨ energy: find the doc, yeet the old one, drop the new one in. periodt.

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🌸 SYNOPSIS 🌸

bool
mongoc_collection_replace_one (mongoc_collection_t *collection,
                               const bson_t *selector,
                               const bson_t *replacement,
                               const bson_t *opts,
                               bson_t *reply,
                               bson_error_t *error);

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🎀 PARAMETERS 🎀

• collection — a mongoc_collection_t. like, the collection we're doing this to. main character.
• selector — a bson_t holding the query that matches the document you're updating. this is how we find our target 🔍
• replacement — a bson_t holding the replacement document. the new fit. 💃
• reply — a maybe-NULL pointer to overwritable storage for a bson_t that'll contain the results. lowkey optional, highkey useful.
• error — an optional location for a bson_error_t, or NULL if you're feeling brave 🙈

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opts can be NULL, or a BSON document with extra command options. here's the whole menu, no cap:

• writeConcern — construct a mongoc_write_concern_t and use mongoc_write_concern_append() to add the write concern to opts. check the example code for mongoc_client_write_command_with_opts(), iykyk.
• sessionId — first, construct a mongoc_client_session_t with mongoc_client_start_session(). you can begin a transaction with mongoc_client_session_start_transaction(), optionally with a mongoc_transaction_opt_t that overrides the options inherited from collection, and use mongoc_client_session_append() to add the session to opts. see the example code for mongoc_client_session_t 🫶
• validate — construct a bitwise-or of all desired bson_validate_flags_t. set it to false to skip client-side validation of the BSON documents you provided. (skipping validation? bold. iconic, but bold. 💅)
• comment — a bson_value_t specifying the comment to attach to this command. it'll show up in log messages, profiler output, and currentOp output. requires MongoDB 4.4 or later ⭐
• bypassDocumentValidation — set to true to skip server-side schema validation of the provided BSON documents. living dangerously, love that for you 🦋
• collation — configure textual comparisons. see Setting Collation Order, and the MongoDB Manual entry on Collation. collation requires MongoDB 3.2 or later — otherwise an error is returned. no exceptions, bestie 💀
• hint — a document or string that specifies the index to use to support the query predicate.
• upsert — when true, creates a new document if no document matches the query. no match? no problem, we invent one ✨
• let — a BSON document consisting of any number of parameter names, each followed by definitions of constants in the MQL Aggregate Expression language.
• sort — specify a sort order when matching documents.

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🦋 DESCRIPTION 🦋

this function shall replace documents in collection that match selector with replacement. simple as that, honestly. 🎯

if provided, reply will be initialized and populated with the fields matchedCount, modifiedCount, upsertedCount, and optionally upsertedId if applicable. if there's a server error, then reply contains either a writeErrors array with one subdocument, or a writeConcernErrors array. either way, the reply must be freed with bson_destroy(). don't forget, or that memory's just gonna sit there rotting 😭

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🔥 ERRORS 🔥

errors are propagated via the error parameter. that's the whole vibe. short and sweet.

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👑 RETURNS 👑

returns true if successful. returns false and sets error if there are invalid arguments, or a server or network error. 💔

a write concern timeout or write concern error is considered a failure. like, she said yes but then ghosted you. still a no. 💀

👀 SEE ALSO 👀

• the MongoDB update command documentation, for more info on the update options 📚
• mongoc_collection_update_one()
• mongoc_collection_update_many()

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🌈 AUTHOR 🌈

MongoDB, Inc — the legends themselves 🫶

⭐ COPYRIGHT ⭐

2009-present, MongoDB, Inc.

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and that's the whole page, bestie! ✨ this was libmongoc version 2.5.6, dated Oct 09, 2026 — mwah, go forth and replace responsibly 💖🎀