MONGOC_COLLECTION_FIND_AND_MODIFY

NAME

mongoc_collection_find_and_modify - mongoc_collection_find_and_modify()

SYNOPSIS

bool
mongoc_collection_find_and_modify (mongoc_collection_t *collection,
const bson_t *query,
const bson_t *sort,
const bson_t *update,
const bson_t *fields,
bool _remove,
bool upsert,
bool _new,
bson_t *reply,
bson_error_t *error);

PARAMETERS

	•		collection: A mongoc_collection_t.
	•		query: A bson_t containing the query to locate target document(s).
	•		sort: A bson_t containing the sort order for query.
	•		update: A bson_t containing an update spec.
	•		fields: An optional bson_t containing the fields to return or NULL.
	•		_remove: If the matching documents should be removed.
	•		upsert: If an upsert should be performed.
	•		_new: If the new version of the document should be returned.
	•		reply: Optional pointer to an uninitialized bson_t that will be initialized with the result.
	•		error: An optional location for a bson_error_t or NULL.

DESCRIPTION

Update and return an object.

This is a thin wrapper around the findAndModify command. Either update or _remove arguments are required.

As of MongoDB 3.2, the mongoc_write_concern_t specified on the mongoc_collection_t will be used, if any.

reply is always initialized, and must be freed with bson_destroy().

ERRORS

Errors are propagated via the error parameter.

RETURNS

Returns either the document before or after modification based on the _new parameter.

A write concern timeout or write concern error is considered a failure.

SEE ALSO:

mongoc_collection_find_and_modify_with_opts().

EXAMPLE

find-and-modify.c

#include <mongoc/mongoc.h>
#include <stdio.h>

int
main (void)
{
mongoc_collection_t *collection;
mongoc_client_t *client;
const char *uri_string =
"mongodb://127.0.0.1:27017/?appname=find-and-modify-example";
mongoc_uri_t *uri;
bson_error_t error;
bson_t *query;
bson_t *update;
bson_t reply;
char *str;

mongoc_init ();

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;
}

mongoc_client_set_error_api (client, 2);
collection = mongoc_client_get_collection (client, "test", "test");

/*
* Build our query, {"cmpxchg": 1}
*/
query = BCON_NEW ("cmpxchg", BCON_INT32 (1));

/*
* Build our update. {"$set": {"cmpxchg": 2}}
*/
update = BCON_NEW ("$set", "{", "cmpxchg", BCON_INT32 (2), "}");

/*
* Submit the findAndModify.
*/
if (!mongoc_collection_find_and_modify (collection,
query,
NULL,
update,
NULL,
false,
false,
true,
&reply,
&error)) {
fprintf (stderr, "find_and_modify() failure: %s\n", error.message);
return EXIT_FAILURE;
}

/*
* Print the result as JSON.
*/
str = bson_as_canonical_extended_json (&reply, NULL);
printf ("%s\n", str);
bson_free (str);

/*
* Cleanup.
*/
bson_destroy (query);
bson_destroy (update);
bson_destroy (&reply);
mongoc_collection_destroy (collection);
mongoc_uri_destroy (uri);
mongoc_client_destroy (client);

mongoc_cleanup ();

return EXIT_SUCCESS;
}

AUTHOR

MongoDB, Inc

COPYRIGHT

2017-present, MongoDB, Inc