bionic (3) mongoc_collection_update_one.3.gz

NAME

       mongoc_collection_update_one - mongoc_collection_update_one()

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.

       • opts: A bson_t containing additional options or NULL.

       • reply: Optional. An uninitialized bson_t populated with the update result, or NULL.

       • 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.

       • 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:    Construct    a   mongoc_client_session_t   with   mongoc_client_start_session   and   use
         mongoc_client_session_append   to   add   the   session   to   opts.   See   the   example   code   for
         mongoc_client_session_t.

       • validate: Set to false to skip client-side validation of the provided BSON documents.

       • 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.

       • 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.

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

       • upsert A boolean, when true, creates a new document if no document matches the query.

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  "modifiedCount"  and  "matchedCount".  If  a
       document  was  upserted,  reply  contains  an  "upsertedId"  field. 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().

SEE ALSO

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

       mongoc_collection_update_many

       mongoc_collection_replace_one

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.

       If provided, reply will be initialized and populated with the  fields  matchedCount,  modifiedCount,  and
       optionally upsertedId if applicable.

EXAMPLE

       example-update.c.INDENT 0.0

          #include "mongoc.h"

          int
          main (int argc, char **argv)
          {
             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 err = {0};
             mongoc_cursor_t *cursor;
             mongoc_client_t *client =
                mongoc_client_new ("mongodb://localhost:27017/?appname=example-update");
             mongoc_collection_t *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, &err)) {
                fprintf (stderr, "insert failed: %s\n", err.message);
                return EXIT_FAILURE;
             }

             if (!mongoc_collection_update_one (
                    coll, selector, update, NULL, NULL, &err)) {
                fprintf (stderr, "update failed %s\n", err.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_client_destroy (client);
             return EXIT_SUCCESS;
          }

AUTHOR

       MongoDB, Inc

COPYRIGHT

       2018, MongoDB, Inc