---
name: "mongoc_database_read_command_with_opts"
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_database_read_command_with_opts"
---

# mongoc\_database\_read\_command\_with\_opts(3)

## SYNOPSIS

```
bool
mongoc_database_read_command_with_opts (mongoc_database_t *database,
                                        const bson_t *command,
                                        const mongoc_read_prefs_t *read_prefs,
                                        const bson_t *opts,
                                        bson_t *reply,
                                        bson_error_t *error);
```

Execute a command on the server, applying logic that is specific to commands that read, and taking the MongoDB server version into account. To send a raw command to the server without any of this logic, use *mongoc\_database\_command\_simple()*.

Use this function for commands that read such as "count" or "distinct".

Read preferences, read concern, and collation can be overridden by various sources. In a transaction, read concern and write concern are prohibited in **opts** and the read preference must be primary or NULL. The highest-priority sources for these options are listed first in the following table. No write concern is applied.

| | | |
| --- | --- | --- |
| Read Preferences | Read Concern | Collation |
| **read\_prefs** | **opts** | **opts** |
| Transaction | Transaction |  |
| **database** |  |  |

*See the example for transactions* and for *the "distinct" command with opts*.

**reply** is always initialized, and must be freed with *bson\_destroy()*.

This function is considered a retryable read operation. Upon a transient error (a network error, errors due to replica set failover, etc.) the operation is safely retried once. If **retryreads** is false in the URI (see *mongoc\_uri\_t*) the retry behavior does not apply.

Retry logic occurs regardless of the underlying command. Retrying **mapReduce** has the potential for degraded performance. Retrying a **getMore** command has the potential to miss results. For those commands, use generic command helpers (like *mongoc\_database\_command\_with\_opts()*) instead.

## PARAMETERS

- •

  **database**: A *mongoc\_database\_t*.

- •

  **command**: A *bson\_t* containing the command specification.

- •

  **read\_prefs**: An optional *mongoc\_read\_prefs\_t*.

- •

  **opts**: A *bson\_t* containing additional options.

- •

  **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:

- •

  **readConcern**: Construct a *mongoc\_read\_concern\_t* and use *mongoc\_read\_concern\_append()* to add the read concern to **opts**. See the example code for *mongoc\_client\_read\_command\_with\_opts()*. Read concern requires MongoDB 3.2 or later, otherwise an error is returned.

- •

  **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 **database**, and use *mongoc\_client\_session\_append()* to add the session to **opts**. See the example code for *mongoc\_client\_session\_t*.

- •

  **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.

- •

  **serverId**: To target a specific server, include an int32 "serverId" field. Obtain the id by calling *mongoc\_client\_select\_server()*, then *mongoc\_server\_description\_id()* on its return value.

Consult *the MongoDB Manual entry on Database Commands* for each command's arguments.

## 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.

## EXAMPLE

See the example code for *mongoc\_client\_read\_command\_with\_opts()*.

## AUTHOR

MongoDB, Inc

## COPYRIGHT

2009-present, MongoDB, Inc.