mongoc_collection_find_and_modify man page

mongoc_collection_find_and_modify() — Update and return an object.

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.

See also: mongoc_collection_find_and_modify_with_opts

NOTE

As of MongoDB 3.2 and mongoc 1.3.0, the mongoc_write_concern_t specified on the mongoc_collection_t will be used, if any.

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.

Example

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

int
main (int   argc,
      char *argv[])
{
   mongoc_collection_t *collection;
   mongoc_client_t *client;
   bson_error_t error;
   bson_t *query;
   bson_t *update;
   bson_t reply;
   char *str;

   mongoc_init ();

   client = mongoc_client_new ("mongodb://127.0.0.1:27017/?appname=find‐and‐modify‐example");
   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 1;
   }

   /*
    * Print the result as JSON.
    */
   str = bson_as_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_client_destroy (client);

   mongoc_cleanup ();

   return 0;
}

Colophon

This page is part of MongoDB C Driver. Please report any bugs at https://jira.mongodb.org/browse/CDRIVER.

Info

2016‐11‐07 MongoDB C Driver