bool mongoc_collection_insert (mongoc_collection_t *collection, mongoc_insert_flags_t flags, const bson_t *document, const mongoc_write_concern_t *write_concern, bson_error_t *error);
This function shall insert document into collection.
If no _id element is found in document, then a bson_oid_t will be generated locally and added to the document. If you must know the inserted document's _id, generate it in your code and include it as the first field of document. The _id you generate can be a bson_oid_t or any other non-array BSON type.
Errors are propagated via the error parameter.
true if the document was successfully inserted, otherwise false and error is set.
A write concern timeout or write concern error is considered a failure.