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
: Abson_t
containing the query to match the document for updating.update
: Abson_t
containing the update to perform. If updating with a pipeline, abson_t
array.reply
: A maybe-NULL
pointer to overwritable storage for abson_t
to contain the results.error
: An optional location for a bson_error_t orNULL
.
opts
may be NULL or a BSON document with additional command options:
writeConcern
: Construct a mongoc_write_concern_t and use mongoc_write_concern_append() to add the write concern toopts
. See the example code for mongoc_client_write_command_with_opts().sessionId
: First, construct a mongoc_client_session_t with mongoc_client_start_session(). You can begin a transaction with mongoc_client_session_start_transaction(), optionally with a mongoc_transaction_opt_t that overrides the options inherited fromcollection
, and use mongoc_client_session_append() to add the session toopts
. See the example code for mongoc_client_session_t.validate
: Construct a bitwise-or of all desiredbson_validate_flags_t
. Set tofalse
to skip client-side validation of the provided BSON documents.comment
: Abson_value_t
specifying the comment to attach to this command. The comment will appear in log messages, profiler output, and currentOp output. Requires MongoDB 4.4 or later.bypassDocumentValidation
: Set totrue
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. Collation requires MongoDB 3.2 or later, otherwise an error is returned.hint
: A document or string that specifies the index to use to support the query predicate.upsert
: When true, creates a new document if no document matches the query.let
: A BSON document consisting of any number of parameter names, each followed by definitions of constants in the MQL Aggregate Expression language.arrayFilters
: An array of filters specifying to which array elements an update should apply.sort
: Specify a sort order when matching documents.
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 matchedCount
, modifiedCount
, and optionally upsertedId
if applicable. 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()
.
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.
Example¶
#include <mongoc/mongoc.h>
int
main(void)
{
mongoc_init();
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 error = {0};
mongoc_cursor_t *cursor;
mongoc_client_t *client;
mongoc_collection_t *coll;
const char *uri_string = "mongodb://localhost:27017/?appname=example-update";
mongoc_uri_t *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;
}
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, &error)) {
fprintf(stderr, "insert failed: %s\n", error.message);
return EXIT_FAILURE;
}
if (!mongoc_collection_update_one(coll, selector, update, NULL, NULL, &error)) {
fprintf(stderr, "update failed: %s\n", error.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_uri_destroy(uri);
mongoc_client_destroy(client);
mongoc_cleanup();
return EXIT_SUCCESS;
}
See also