MONGOC_COLLECTION_UPDATE_ONE(3)

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