---
name: "mongoc_collection_replace_one"
section: "3"
platform: "linux"
package: "libmongoc-doc"
version: "1.30.4-1+deb13u3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/mongoc_collection_replace_one"
---

# mongoc\_collection\_replace\_one(3)

## 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);
```

## PARAMETERS

- •

  **collection**: A *mongoc\_collection\_t*.

- •

  **selector**: A *bson\_t* containing the query to match the document for updating.

- •

  **replacement**: A *bson\_t* containing the replacement document.

- •

  **reply**: A maybe-**NULL** pointer to *overwritable storage* for a *bson\_t* to contain the results.

- •

  **error**: An optional location for a *bson\_error\_t* or **NULL**.

**opts** may be NULL or a BSON document with additional command options:

- •

  **writeConcern**: Construct a *mongoc\_write\_concern\_t* and use *mongoc\_write\_concern\_append()* to add the write concern to **opts**. See the example code for *mongoc\_client\_write\_command\_with\_opts()*.

- •

  **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 to **false** to skip client-side validation of the provided BSON documents.

- •

  **comment**: A *bson\_value\_t* specifying the comment to attach to this command. The comment will appear 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.

- •

  **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.

- •

  **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.

- •

  **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.

## DESCRIPTION

This function shall replace documents in **collection** that match **selector** with **replacement**.

If provided, **reply** will be initialized and populated with the fields **matchedCount**, **modifiedCount**, **upsertedCount**, and optionally **upsertedId** if applicable. If there is a server error then **reply** contains either a **writeErrors** array with one subdocument or a **writeConcernErrors** array. The reply must be freed with *bson\_destroy()*.

## ERRORS

Errors are propagated via the **error** parameter.

## 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.

**SEE ALSO:**

```
MongoDB update command documentation for more information on the update options.
```

```
mongoc_collection_update_one()
```

```
mongoc_collection_update_many()
```

## AUTHOR

MongoDB, Inc

## COPYRIGHT

2009-present, MongoDB, Inc.