mongoc_collection_update_one − mongoc_collection_update_one()
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);
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collection: A mongoc_collection_t. | ||
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selector: A bson_t containing the query to match the document for updating. | ||
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update: A bson_t containing the update to perform. If updating with a pipeline, a bson_t array. | ||
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reply: Optional. An uninitialized bson_t populated with the update result, or NULL. | ||
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error: An optional location for a bson_error_t or NULL. |
opts may be NULL or a BSON document with additional command options:
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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(). | ||
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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 from collection, and use mongoc_client_session_append() to add the session to opts. See the example code for mongoc_client_session_t. | ||
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validate: Construct a bitwise−or of all desired bson_validate_flags_t. Set to false to skip client−side validation of the provided BSON documents. | ||
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comment: A bson_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. | ||
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bypassDocumentValidation: Set to true to skip server−side schema validation of the provided BSON documents. | ||
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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. | ||
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hint: A document or string that specifies the index to use to support the query predicate. | ||
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upsert: When true, creates a new document if no document matches the query. | ||
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let: A BSON document consisting of any number of parameter names, each followed by definitions of constants in the MQL Aggregate Expression language. | ||
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arrayFilters: An array of filters specifying to which array elements an update should apply. |
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 are propagated via the error parameter.
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−update.c
#include "mongoc/mongoc.h" int main (void) { 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); return EXIT_SUCCESS; }
SEE ALSO:
MongoDB update command documentation for more information on the update options.
mongoc_collection_update_many()
mongoc_collection_replace_one()
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