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MONGOC_COLLECTION_FIND_AND_MODIFY(3) libmongoc MONGOC_COLLECTION_FIND_AND_MODIFY(3)

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

August 31, 2022 1.23.0