Man page - mongoc_collection_update_one(3)

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Manual

MONGOC_COLLECTION_UPDATE_ONE

SYNOPSIS
PARAMETERS
DESCRIPTION
ERRORS
RETURNS
EXAMPLE
AUTHOR
COPYRIGHT

SYNOPSIS

bool
mongoc_collection_update_one (mongoc_collection_t *collection,
const bson_t *selector,
const bson_t *update,
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.

•

update : A bson_t containing the update to perform. If updating with a pipeline, a bson_t array.

•

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.

•

arrayFilters : An array of filters specifying to which array elements an update should apply.

•

sort : Specify a sort order when matching documents.

DESCRIPTION

This function updates at most one document in collection that matches selector .

To update multiple documents see mongoc_collection_update_many() .

If you pass a non-NULL reply , it is filled out with fields matchedCount , modifiedCount , 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.

EXAMPLE

example-update.c

#include <mongoc/mongoc.h>

int
main (void)
{
mongoc_init ();
bson_t *to_insert = BCON_NEW ("_id", BCON_INT32 (1));
bson_t *selector = BCON_NEW ("_id", "{", "$gt", BCON_INT32 (0), "}");
bson_t *update = BCON_NEW ("$set", "{", "x", BCON_INT32 (1), "}");
const bson_t *next_doc;
char *to_str;
bson_error_t error = {0};
mongoc_cursor_t *cursor;
mongoc_client_t *client;
mongoc_collection_t *coll;
const char *uri_string = "mongodb://localhost:27017/?appname=example-update";
mongoc_uri_t *uri = mongoc_uri_new_with_error (uri_string, &error);

if (!uri) {
fprintf (stderr,
"failed to parse URI: %s\n"
"error message: %s\n",
uri_string,
error.message);
return EXIT_FAILURE;
}

client = mongoc_client_new_from_uri (uri);
if (!client) {
return EXIT_FAILURE;
}

coll = mongoc_client_get_collection (client, "db", "example_coll");

mongoc_client_set_error_api (client, 2);
/* insert a document */
if (!mongoc_collection_insert_one (coll, to_insert, NULL, NULL, &error)) {
fprintf (stderr, "insert failed: %s\n", error.message);
return EXIT_FAILURE;
}

if (!mongoc_collection_update_one (coll, selector, update, NULL, NULL, &error)) {
fprintf (stderr, "update failed: %s\n", error.message);
return EXIT_FAILURE;
}

to_str = bson_as_relaxed_extended_json (to_insert, NULL);
printf ("inserted: %s\n", to_str);
bson_free (to_str);

cursor = mongoc_collection_find_with_opts (coll, selector, NULL, NULL);
BSON_ASSERT (mongoc_cursor_next (cursor, &next_doc));
printf ("after update, collection has the following document:\n");

to_str = bson_as_relaxed_extended_json (next_doc, NULL);
printf ("%s\n", to_str);
bson_free (to_str);

BSON_ASSERT (mongoc_collection_drop (coll, NULL));

bson_destroy (to_insert);
bson_destroy (update);
bson_destroy (selector);
mongoc_collection_destroy (coll);
mongoc_uri_destroy (uri);
mongoc_client_destroy (client);
mongoc_cleanup ();
return EXIT_SUCCESS;
}

SEE ALSO:

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

mongoc_collection_update_many()

mongoc_collection_replace_one()

AUTHOR

MongoDB, Inc

COPYRIGHT

2009-present, MongoDB, Inc.